I signed up on Twitter and FriendFeed recently and I've been testing them out. While Twitter seems best to keep things social, FriendFeed seems best to keep things organized.

Twitter is nice as a mini-journal where you post tid-bits of information. Similar to Qassia, except its designed specifically for small amounts of information and its easy to subscribe to your friends Twitter feeds to keep tabs on them :P

FriendFeed is really cool, because it can help you organize all of your feeds from many sources (like YouTube, StumbleUpon and more). This is similar to Yahoo Pipes, except it's easier to use and you should probably be using your own feeds, not others feeds like from News sites or Donald Trumps blog.

These social sites are possible traffic sources as well. Since I'm just starting out on them still, we'll have to see how it goes. I'll keep you posted.