Come to Gaia Online! Right now, the big event until 7/31 is the "Rejected Olympics", something they throw every four years in parody of the real Olympics.
This year, one of the events just happens to be Paintball! Once you've joined the service and picked which Town you want to represent (I represent Isle de Gambino), you "shoot" every other player who is not on your team just by clicking your mouse. Your avatar may end up totally splattered all over, but that only lasts while you're in that particular Event.
I saw this, and went LOL....and thought of all the Paintball players who frequent this Forum. I leave it up to y'all to come over and try things out for yourself.
The only plug-in you'll need for the Events is the latest version of Adobe's Flash.