Vitamin's Ryan Carson just wrote a piece about why he doesn't use Social Software. He basically says he's too busy.
Facebook is the only on-line service that has it right at such a complicated level. They have a nice group of services (blog, photo, notes, calendar, groups, friends) and a decent one stop interface to follow along.
The secret is that all the services write a "story" which is aggregated into a continious story of your on-line life.
I'll have to see how well integrated they are with Google Personalized Home Page and MyYahoo.