I've just gotten myself into a new hobby (besides writing music, and lasers), it's called Airsoft.
For those of you that haven't heard of this sport, it was originally developed in Japan or China (asia somewhere) because the laws there don't allow people to own real guns, but replica guns are allowed for some reason. The sport is growing here in the US, originally intended for training military and police personnel, then it just grew to the general public.
These guns are usually exact replicas of their "real steel" counterparts, right down to the moving slide on semi-automatic pistols, and magazines, and most rifles (called AEG's) have selectable auto-semi auto action. The guns fire small 6mm plasic bb's and can travel at a rate of 200fps up to and probably beyond 500fps (anything beyond may be illegal in your area, check your local laws regarding Airsoft).
There are several Airsoft clubs throughout the US, that routinely have "skirmishes" on either an official Airsoft/Paintball field, or on private property.
If anybody wants to get into this sport, I urge you to double check with your local law enforcement about the legality in your area. Since Airsoft guns look real (except for the required orange plug at the barrel), they may be mistaken for a real firearm by law enforcement, or citizens. Please be careful.