Paintball gear is intended for the sport of paintball, but that doesn't mean there's nothing else it can be used for. Here are just a few of the legitimate things paintball equipment can be used for. Note: vandalism, threatening people, intimidation and general mischief are not useful things. Please don't suggest them.
Marking Trees and Livestock
The original paintball gun wasn't intended to be used for a sport, it was designed to mark trees and livestock without needing to get close to them. That's where the term "marker" came from.
Art
Painting from a distance has always been an interest of modern artists and paintball guns are a great medium whether its a team-based approach or something a little faster.
Movie Props
Countless home-made movies have used paintball guns in the place of real guns. When you don't have a tank or hopper and kind of squint, they work. Paintball pistols are especially popular to use as they more accurately reflect the shape of real guns. Remember, if you want to use a paintball gun as a prop, make sure that no air source is attached to the gun so there is no risk of it firing.
Pest Control
A blast of air from a paintball gun without shooting a paintball is usually sufficient to kill spiders and other small insects from a safe distance for the arachnophobes out there.
Conversation Starter
Boring party? Sick of talking about politics? Invite someone to see your paintball gun. Just showing off your gear will get any conversation going. Showing someone what paintball gear is also a great way to get them interested in the spot.
Protection
In a pinch, use your mask if you don't have safety glasses. I actually prefer a paintball mask to normal goggles when I use a grinder.
Billiards
The Pneu Power Cue uses standard paintball guns and adds a pneumatic cue to the tip and lets you shoot pool with a trigger.

