Google Buzz looks pretty cool. More useful than Google Wave at least, since it’s connected directly to your Gmail, rather than being a separate website.
It feels like a mix of Twitter (quick short posts) and Facebook (links, videos, etc.).
My Gmail is only for class/work stuff, so the “automatic follow” list is professional contacts and groupmates. The people I know best I talk to in person, on the phone, or on Facebook. Kinda useless.