Social Networking, the Next Generation

I've been playing with some more Google applications recently, and in switching between them and my home on FaceBook, it strikes me that while Google also seems to be building out a platform that could be considered "social networking," they're doing it in a very different way.

Social networking sites like FaceBook, MySpace, Friendster, and the like are really just lists of lists: these people are my friends, these people aren't my friends, these are the things I like, etc. Google's platform (if it's not too early to use that word) is about what its users are actually reading (Reader), thinking about (Blogger), talking about (GMail and GoogleTalk), and doing (YouTube).

Sure, you can make a list of your favorite web sites on FaceBook, but that list is totally decoupled from what you're actually reading. Google Reader, by contrast, serves a useful purpose as a standalone applications -- it aggregates RSS feeds, for those who haven't tried it -- but it also ties into other Google services. You can, for example, flag the articles you found most interesting, and make them show up in a pane on your blog. (I've got one of those myself; check out the new sidebar. Haven't figured out how to make it look decent yet, unfortunately.)

All of which leads me to something I'm really curious about: which side will Twitter come down on, and why hasn't anyone bought them yet?