Heh, I haven't fought a laser battle since one of mate's birthday parties when I was about 8. I didn't really like it much, very unsatisfying - you have to aim at a small square on their chest/back, and your gun doesn't even have any sights. :?
Always wanted to go paintballing, though, shame it's so expensive. Here in Scotland, it costs about ?50 to go paintballing - that's ?40 to get in, and ?10 for extra ammo (which you kind of need). I'd be happy to pay, but most of my friends aren't, and I wouldn't want to play with strangers. :(
There's also BB gun fights (low powered air guns, with plastic pellets), that'd be a bit more like the 'real thing'. A chance to play soldiers without getting hurt too much, and a bit more realistic than paintballing. You don't have to wear the daft overalls anyway.

But I don't know anywhere in Scotland that does BB fights, and it'd probably be even more expensive than paintballing, if you have to rent equipment. And it costs over ?100 for an automatic BB gun.