(well damn... I typed a long response, but the window refreshed and I lost it!)

Really quickly, I bought the Archos 20GB recorder over the Riot. I didn't like the "curvy game boy" form factor of the Riot. The menus and UI of the Riot are more advanced than the Archos, but the Archos can be easily used as a simple hard-drive device. Just plug in, copy, and go... no software necessary.

I'd be glad to answer any specific questions...