
I'm testing Yahoo! 360°. It seems very cool, works fine, you can classify you contacts in categories and import your contacts from Yahoo! Messenger, Yahoo! Address Book and Microsoft Outlook. It has integration with many, maybe all, Yahoo! services: My Yahoo!, Yahoo! Mail, Yahoo! Photos, Yahoo! Local, Yahoo! Groups and Yahoo! Music.
As all the new social network sites you can create a blog, share cool links or ideas with the Blast, share photos, local reviews, add friends, listen LAUNCHcast music station, create and share lists of your favorite books, movies, music, show to your friends, or everybody your groups on Yahoo!.
Steve Rubel wrote a mini review about Yahoo!360° on his page there, but you can read it also on Micro Persuasion. Read also the initial impression of Yahoo! 360° of Danah Boyd, Marc Hedlund and Clay Shirky reviews.
BTW, the invites are limited to 100 and that is one more reason for just invite people that you know. And that is what I will do. So, if I don't know you I will not send you an invite. Sorry (I had some problems with this on my Gazzag entry). But don't worry, sooner or later someone that you know will invited you. Anyway, you can find me there on my Yahoo! 360° page.