Here’s a list of several tools enabling you to manage content from various services from the one spot.
Some of these tools cover a breadth of services like IM, email, and networks, and some even allow you to update multiple sites at the same time.
Leave a comment if you have tools to add to this list.
Hellotxt (also mobile)
Ping.fm (also mobile)
Utterz (also mobile)
mobypicture (also mobile)
[ADDED 20/03/09: Presencr]
[29/04/09: Quub (also desktop/mobile)]
Streams, content centrality and social graphing
Email is not the centre of my universe!
Centralising distributed social networks
Centre of my web 2.0 universe
Social network and graph ecology