I LARP, and don't quite get the revultion it seems to cause around here. Sure, I can imagine it seems very strange to people who don't get the appeal of it, but then again, so do all gaming.
What most outsiders see is a bunch of people in pseudo-medieval armor beating the shit out of each other with rubber swords. What many outsiders don't realize, however, is that many LARP groups are tightly knit communities wherein close friendships prosper. Also, getting into the gear and getting out to try some things you certainly won't in your boring everyday life can be a quite nice experience. I have many fond memories of LARPing, but I will spare you from them now : )
Another commonly held misconception is that LARPers are freakish nerds with no life - I must say, though I've certainly met quite a handful of those types in the 5 years that've passed since my first LARP-session, most of the serious LARPers I know certainly aren't no-lifers. They get drunk, laid and do stupid stuff frequently, just like "the cool kids" do (not saying that it's necessarily a good thing, just that they're not rotting in their basements when not playing elves and orcs in the forest)
I must note, however, that I'm from Denmark, and I have the impression that the LARP-milieu here is quite different from that in, say, The States, so what I've said might not be true in other parts of the world.
(also, excuse poor sentence structure, typed this at crap 'o' clock in the night)