my small group i've been rp-ing with for about 3 years are some of my best friends. 3 of us actually met a couple years ago - and we don't live close by. it involved buying VERY expensive plane tickets... but so worth it!
i don't get this anti-ooc thing either. how are you supposed to plot and come up with epic storylines if you don't talk? and plotting usually turns to "oh, i once knew someone who did that" type of talk.
i DO agree with what deepwithin said, about it being harder to tell close friends that you don't like the line you're in. it almost feels like you're ending something with THEM, rather than with the character.