Orkut is the first official digital social network I've joined. Robert Scoble (thanks!) sent me an invitation on Friday, and I sent invitations to a bunch of my friends and so the system grows.
It's a pretty cool place to hang out. At first I was like, so what's the big deal? But now that it's been a few days, and I've joined a bunch of communities, I'm finding the whole thing pretty cool.
The site is built in ASP.NET (cool). Overall design, usability, and speed is great. I think it's going to be a fun place to hang out.