I've been experimenting with Calibre.
So far, I'm kinda wondering how you use the embedded fonts, but after reading one of the sticky threads in that forum, I at least have sans-serifs working, I just can't yet prove what typeface it is!
I've been dithering on one of these for a while, now.
My friends, who have a 505 and 500 each, were oh, so sympathetic last night: "Out of the box less than an hour and bricked already!"
With friends like these...
-JPB