I’m not sure how fast they are going to continue handing out invites, but I had a beta invite for FriendBinder within an hour of signing up for one.
I could summarize it, but I would only be re-inventing what Louis Gray summarized on his blog.
I would say the sign up and service-adding process is very slick; for most services, all you need to do is enter your username. Adding friends from the other services was trivial, one click each.
FriendBinder is very close to an imaginary service I thought up and was wanting about two years ago… I’ll be interested to see if it is as useful as the (at the time) mythical service I was picturing.
Incidentally, I think del.icio.us could also easily step into this space, by allowing you to aggregate items from other feeds as well. If they did that, and marketed the social networking side of del.icio.us a little better, I think it’s possible I might even prefer it to some of the other services currently available.