FriendFeed

As I've mentioned before when discussing lifestreaming, FriendFeed is a way to aggregate all the various pieces of your life together in one place (well, the pieces you can remember about anyway).

In addition to this, it provides a centralised place to rate and discuss any of the elements you post, regardless of their source.  This enables discussion threads around e.g. a Twitter item, a kind of structured discussion that is not (easily) possible to have within Twitter itself (see e.g. Darren Barefoot's posting about this issue).

There are quite a few people in FriendFeedspace now, and I'm back posting after a vacation, so here's mine

http://friendfeed.com/scilib

Although it doesn't have dedicated support for every possible service, you can hack FF a bit by putting any RSS feed into the "blog" section.  I probably have a few more sources to add but the major ones are there.