During the UI Hackfest in Boston a lot of ideas have been sketched and some of them already under development! The one that caught my attention the most was Federico's Presentation. If this can be turned into reality it could be a step forward to reach Gnome 3.0.
It saddens me however that some of the ideas in the presentation have been already developed in Gimmie before. Gimmie provides a semi History browsing for everything from documents to applications and even Pidgin chats.
All it would take is some modifications to the Gimmie code and u got yourself a kick ass application that fulfills all of the Points set by Federico.
Here is a take on the Gimmie/Mayanna based version. It had some memory issues but all in all it does a pretty nice job for a timeline.
It updates on new events and supports tagging into favorites... its not much but it is a good example for an approach! I will give myself more time soon to really modify it all!