UPDATE: So I bought and tested a couple of movies from www.moviehd.com last night and here's the scoop: The iPod versions (resolution roughly 480x320) work best on the eDGe. They're beautiful, sound good, too. The other formats either don't work or don't work well because the resolution is too high or the codec isn't supported. The iPod versions also work well on a PC. Haven't yet tested it on my BlackBerry but will.

I also checked in with tech support for their input, and they said, "The enTourage eDGe currently support [sic] MP4 videos with resolution up to 480x320. DivX will play on the eDGe but fewer of the encoding options are supported as compared to h.264."