I've been a member of Second Life for a year and a half now, and have nothing but positive things to say about it (other than "It should have been free when I joined!" )
I've met some fantastic people there, a couple who have become very good RL friends, and I also hold poetry readings every Monday (just had one!) at 2pm PST at my cyber cafe.
There are some amazingly talented people creating art in SL, and it's worth joining just to be able to glimpse that.