Yep (linky below) - Flickr has been really fun for me and I've got a lot out of it - found fellow photographers who've shared tips and advice, seen some really awesome pictures and also have been contacted through flickr to sell my photos for wall art, a dutch book cover, websites and an exhibition on human rights - all wierd and wonderful things. So well worth it, I think.
The only downsides are people commenting 'great capture' on thousands of people's pics without actually looking at them and the usual gear and technique snobbery, rivalry and the like that any photo site has.
Cheers,
Mel.