I've already written how I use FriendFeed to aggregate all my services into a live stream. You probably have already seen on my About page the different services I use. How did I do this?
I keep track of all my services with 'Retaggr' It allows you to create a profile, register and store all you services in a central place and gives you heaps of possibilities to use this in various ways, some examples are:
1. A profile card to show anywhere. The card can be customized to your needs.
2. A profile page that shows all your information in a central page.
3. An embed able profile button:
4. Widget to use in you blog as I did on my About page.
5. A cool a button. Feel free to click the button.
I really like this Retaggr - The Definite Online Profile. You can read more at the Retaggr Blog