spok

How about the "spok" method :D? To be more exact (so that non trekkies will understand as well ;D) spok disables an other person by pressing a pressure point at you neck (i think), very martial arts style :D

from injection to projection

There is a hundreds of ways to render a person harmless it all depends on the situation you want. To get placed right. Take for example.

Scene one: The guard room; (our agent is creeping thru the building trying not to be spotted while he look’s over some records or tries to find evidence of a crime, problem is it has guard patrols and a security room.) In this case the agent may need to disable or distract a guard or group of guards) waiting patiently the agent passes unnoticed behind the first patrol sticking to the shadows and hugging walls to avoid cameras. Now he needs to get in the front door of an inmortant room and he notices a finger print id on the door, but there is a camera watching the space just around the corner(so the agent must first disable on of the guards to use his finger then he must make certain no one is watching that camera during his approach with the disabled guard) the agent finds a spot where the guards will pass by him and he is off camera then waits. When the guard walks past the agent kicks the man in the back of the knee to force him to the ground then another swift kick to the gut to force him to expel his air the guard now on all fours grasping for air is powerless to stop the agent from rolling him over and keeping his weight on the guards chest and abdomen so he can’t draw in more air. After about 20 seconds the guard passes out. The guard now passed out our agent disrobes him and takes the clothes for himself binding the guards hands and feet. The Agent now sets off for his next non-lethal distraction. Carefully yet fast the agent makes his way to the other side of the compound where he blocks a camera with a sock then another with the other sock he then fires the guards gun off and leaves it on the ground rushing back to his unconscious guard he stands with his back to the guards coming out to check and then acts like he saw something and chases after it the other two guards follow him around the corner only to trip on his pants that where left as a trip cord. Seeing the other guard round the next corner they call after him but the agent keeps running quickly he ducks into the shadows and waits for the other two guards to rush past him he runs back to the guard he knocked out and throws a shirt over the camera by the door and uses the unconscious guards finger to open the lock he uses a shoe to hold the door while he drags the guard under the camera. Taking the shirt back down and then walks up to the door as if he belonged.

But there are many other ways today to distract people from strobe lights to t.v sets even the raido could be useful. If you can control what is on a broadcast and know someone is listening to it you could easily gain much of there attention away from the rest of the world.

If you planted some explosives before walking up to use as a diversion on the other side of a building for example. No casualties just loud and bright. This could easily by 20 seconds on the other side of a building.

Of course then you could always use a needle filled with what ever your writer wants to call it have some one talk about it I.E. the conversation “Q” and "Bond" always had to describe it to your audience and boom one syringe filled with water or even better a fake needle prop filled with an odd colored water and bam cheep non-lethal knockout you could even put it in a dart gun.

Of course technology can be just as good one projection screen TV could get a nice distraction going. If set up to run a movie on a wall it might provide an overworked guard much distraction thru the night. Set it up on the opposite buildings wall so it can be seen clearly then just play anything form a popular movie, to tv shows, to cartoon sketches to make’em laugh. now you have lots of gaurds takign an extra moment everytime they pass that way maybe even going further if it is lower scerity building.

Hot sauce

For certain feeding-related contexts. Addition of a suitably powerful hot sauce into somebody's food, which is then ingested, may lead to short-time temporary disabling of that person, who suddenly gets a set of mouth-on-fire related problems to immediately take care of. Usually accompanied with a telltale comedic behavior.

A few chosen people from the top ranks of chileheads are virtually immune to such effects. This difference in the individual response rate may be used to lure the victim into thinking that their bottle of ketchup is not spiked with anything dangerous.

Said extreme chileheads, adapted to the effects of capsaicin, also tend to have very attenuated response to pepper spray.

Allergic reactions, less-lethal chemical and biological weapons

Less-lethal approach, though not exactly nonviolent.

A significant segment of the population suffers from one or more allergies. The knowledge of such, gleamed from the target's medical documentation, may allow a disabling attack, with response ranging from a mild discomfort through a rash to a life-threatening and immediate hospitalization requiring anaphylactic shock.

The agent used, depending on the characteristics of the target, may be e.g. some food or an insect.

Spiking target's food with a pathogen may also serve as a less-lethal disabling attack. Salmonella (or, if we want a quick epidemy in a facility, a norovirus) are just some of the possible candidates. A real case happened in 1984, when a cult in Oregon attempted to influence the county elections by incapacitating the voting population in the area by contaminating food in salad bars; genetic forensics, identifying the origin of the pathogen strain used, then led to apprehension of the culprits.
http://en.wikipedia.org/wiki/1984_Rajneeshee_bioterror_attack

Another nasty thing is chloropicrin, also known as "vomit gas". Fairly toxic, but in low doses not too lethal; acts as a lachrymatory agent and causes intense vomiting. Used in WW1 as a chemical weapon; the small molecule penetrated the mask filters and its effects forced the soldier to remove the mask, leading to exposition to more lethal agents. The effect is virtually immediate - can start in as little as 10 seconds. It is commercially available for fumigation and seed and soil sterilization. Gas detection tubes for chloropicrin are commonly available as part of chemical weapon detection sets.
http://en.wikipedia.org/wiki/Chloropicrin
The vapors can linger in the contaminated area, especially if enclosed or underground, acting as an area-denial weapon.
There was a case I heard about years ago of a quarrel between two chemists. One then contaminated the other's office. When the police came to investigate, their dog vomited just by sniffing the door, then the cops followed the poor doggie's example after opening the door and bravely stepping in.

Yet another WW1 material is bromoacetone. A fairly powerful lachrymatory agent. VERY easy to make, frequently used for pranks by students of chemistry. So easy to make it can be prepared by accident when attempting to prepare something else; people often forget that the solvent can act as a reagent too (been there, weeped at the reaction yield).
http://en.wikipedia.org/wiki/Bromoacetone

A commercially available CS gas spray will however do a comparable job; there were numerous cases of shopping centers evacuated or partially evacuated after somebody used a tear gas spray there.
http://en.wikipedia.org/wiki/CS_gas
Rigging such spray can with a pyrotechnic cartridge could provide a tear gas grenade/mine, useful for e.g. non-lethal protection of a facility against intrusion.

A lot of other methods can be gleaned from Schneier's blog, especially from his movie plot terror contests.

An extra-vile way

If you want to REALLY put somebody out of action, there's an endemic specialty available up there. Never underestimate the knock-out power of a bottle of salmari. The next-day lingering hangover is a bonus.

Disabling people by disabling critical technology

People are dependent on technology. Disable a car, and the driver can be stranded in the middle of nowhere. Especially unpleasant in the areas where there's nothing but snow and mooses.

Modern cars are heavily dependent on electronics. An electric paralyzer, carefully applied to the vehicle control unit, and the car has to be towed. Alternatively, just steal the unit. One of the ways to steal cars with immobilizers is swapping the (externally accessible) control unit with another one with known codes.

Older, more classical way is water in gasoline tank. Stays at the bottom of the gasoline tank, gets pumped into the engine, and the engine won't run.
http://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/sugar-in-gas-tank.htm

Emptying the car's tires is another classics.

There are efforts to develop devices to stop cars remotely, usually on the basis of microwave pulses. Discussed e.g. here:
http://tech.slashdot.org/article.pl?sid=07/11/13/2322241
An old car with a mechanical distributor will be immune against those; such vehicles are still to be seen in rural Finland.

An EMP/HERF weapon can be used also against fixed installations. I heard a hearsay about disabling security system by driving around the building with a minivan with plastic back (transparent for radio waves), and a surplus military transceiver with a directional antenna, keyed on and feeding the building with couple kilowatts of radio frequency waves. Reportedly there was a good chance that the security system bought the farm. But I heard it from somebody selling optical comm systems so it may have been marketing.

A cellphone with an attached relay can short out a power line and trip the breakers in a section of a building on command. This may be used as a method to disable the elevators on command, as I suggested earlier.

A rocket with an attached wire, fired from a building roof into a thunderstorm cloud, can attract a lightning into the building. Together with damaged grounding of the lightning rods, the electronics in the building may end up pretty fried. I thought about a high-tech variant, transforming the lightning energy to a directional microwave pulse aimed to a nearby facility.

A cellphone SIM card can be destroyed by powering the phone off (if on), on, then entering a wrong PIN for 5 times. Optionally then entering the wrong PUK 10 times (who remembers the PUK anyway?). Then the card is out of commission and the phone number is not working anymore until a new card is issued by the telco. A stranded person in the middle of nowhere, depending on the cellphone and without it, is out of action for at least hours.

For various wireless fun, not disabling but useful for gathering intelligence, check out my comments at Project WORM.

3-methylfentanyl

Dissolved in halothane, it can be used as an aerosol. An innocent-looking bottle of perfume in a lady's purse may contain a powerful knock-out agent.
http://en.wikipedia.org/wiki/3-methylfentanyl

This chemical was likely already used in tactical situation, though with some casualties, during the Moscow theatre siege in 2002.
http://en.wikipedia.org/wiki/Moscow_hostage_crisis_chemical_agent

Elevator

When the person rides an elevator, wait until it is between the floors, then trip the breaker on the power circuit that feeds the motor. Unless there is a way to passively let the cabin move down, the person stays out of commission until help arrives.

radioactive poisoning:

http://en.wikinews.org/wiki/Former_Russian_spy_Litvinenko_dies%2C_radioactive_poisoning_suspected

Takes more acting than special effects. Any substance will do to represent the radioactive element.

mobile phone

Mobile phones are great aren't they. They have so many applications. This one has earphones to protect the user and when a certain number is dialed a sonic signal is sent to disable anyone in the immediate vacinity. Could even be an add-on son somebody inadvertantly disables themselves.