Idea for Personal Timeline Viewer

As one of my new years resolutions was to not sit on ideas until I get time to implement them (I never do), so I’ve created an “Ideas” category that I can use to write these down. Here’s my first one:
I’d like an application that would build be a personal timeline of my web activity.
Actually, I’m also interested in viewing other people’s activities, but lets get on with describing what I mean.

I maintain a blog, a set of del.icio.us links, a reading list (at All Consuming) and a flickr photo collection. Each of these sites produce an RSS feed with timestamps attached to the activity I generate there: link descriptions, postings, and photos.
If I were organized enough I’d probably maintain a diary too to track travel and events. These would also obviously have dates too.
What I’d like to see is an application that would hoover up content from any RSS feed I generate as I go about my business on the ‘net, and then format the data as a horizontal timeline.
The user interface I’m imagining is big black horizontal timeline that I can scroll along, or zoom in and out of. At a high level the timeline might just show me activity summarised by tags (“Look like in January 2005 I wrote a lot on the Semantic Web, tagged a bunch of stuff under SocialSoftware”). At a more detailed level, attached to the timeline will be actual photo thumbnails, blog entry titles, links, etc.
The seeds for this data (i.e how to find the relevant RSS feeds) can found via my FOAF description. So ideally the application would be configured by pointing it at my FOAF file. As a piece of social software the application would be configured by a collection of FOAF files or RDF blog roll, so I can see an aggregate timeline, e.g. for a community of interest.
The user interface for the aggregate view could be done in several ways. The simplest being to aggregate all activities on a single line. The other to have several parallel lines, with links between them to indicate, e.g. co-depiction in photos, shared creative output, etc.
A related, but simpler request, would be a tool that I would draw me a zoomable, navigable timeline (as SVG?) which I could throw data at. It’d be interesting to generate timelines for historical figures (e.g. Samuel Pepys, Charles Darwin) that could be used to navigate their writings and activities.
I think this’d be an interesting way to explore and present data about people and communities. Does such a beast exist?