Experimenting with the open source Sweetcron in the lab as a lifestream or aggregation platform. Fairly simple LAMPS installation (assuming you remember to turn on mod_rewrite), with a good potential for customization.
Interesting that the project’s founder has switched to Posterous for his own site. Personally, I’m always amazed at how Tumblr (my gracious host) continues to evolve beyond that original concept.