LiveJournal, a blogging web site, lets one name some people as "friends." It's a bit of a misnomer; all it really means is that that person's LJ entries are gathered onto one page (along with those of any other "friends" you have) that you can look at for convenience. The connotations of "friend," though, lead to misunderstandings. When people cull their friends list, they are often apologetic, and people removed from one's "friend" list evidently are sometimes hurt ("Don't you like me any more?"). I think that it would be better renamed to avoid those connotations.
SL has a way to select some people as your friends. Unlike LJ, both parties have to agree; friendship in SL is a symmetric relation, and either party can break it off. Do I think it's a misnomer, like the LJ arrangement? Not as much. In SL, it's more directly about the other person, as opposed to "just" his or her writing.
Some people don't want friendships offered lightly, and that's certainly understandable. I am perhaps too quick to offer friendship; if I talk to someone and seem to get along well with him or her, I'm likely to do so. It's only bitten me once or twice, and thinking back I was a bit uncertain at the time and should've listened to my instincts.
OTOH, it may not be fair to the other person. I can think of one person I've become friends with, and have never seen since. What must they think of me? ("You never write, you never call..." :)) I hesitate to break off such friendships, lest I offend... and even worry that writing this will give my friends the impression that I don't hold their friendship in high regard. (I do; right now, a goodly number of my dearest friends are people I've only seen as their avatars, and very likely never will see in RL.)
I have become a little less ready to offer friendship as time goes on. Perhaps everyone goes through an initial stage of offering lots of people friendship... like wearing boxes. :)
Though I am trying not to be as shy in SL, it still strikes from time to time, as it did in the case that provoked me to write this blog entry. Recently I saw someone so magnificent in dress and in avatar that I was utterly intimidated. I probably never would have dared talk to her, much less offer friendship... but yesterday she struck up a conversation with me, and now we are friends. Thank you, dear lady.