Twitter has announced a new feature: custom timelines. Available on Tweetdeck.
Custom timelines are a new type of timeline you control: you create the timeline, give it a name, and select which Tweets to add, either by hand or programmatically using the API. Timelines are public, have their own pages on twitter.com, and can easily be embedded on your website. The rest is up to you.
Finally, a way to properly organise the chaos that is twitter timeline. Lists helped to make it keep up with tweets easier but managing our tweets has always been out of our control.