I've was looking for an interesting project to get my hands on live maps API. Just to get the hang of developing cool application on top of Live maps.
I've started this Olympics Medal Count + Community Contributed Data + Live Maps Mashup
And It's almost complete.
Take a look at this Beijing 2008 Medals Count on Live Maps
If you want to help complete the picture, make your contribution to this wiki page
Want to get a grip on the Live Earth SDK as well, here is your starting point [Live Earth SDK]