Off topic a bit, but I picked my wife up a Kindle 2 3G from Woot a few days ago, and while hunting around for tweaks and hacks I came across a utility called Savory (google it) that basically runs a tiny version of Caliber ON the Kindle itself. It scans the download directory for ePub and PDF files, and automatically converts them to Kindle files, images and all. On his Google code page there's also a system update that lets the Kindle's browser download those kinds of files. I'm going to try it sometime soon, and would be happy to report back on how (or if) it works.

Coincidentally, my wife has UNstolen my PE since her Kindle came yesterday. So at least THAT worked...