I'd like to know, too...
Currently my only reader is a pocket pc with mobipocket reader installed. My public library has many more books available in Adobe Digital Editions format (don't know it by any other name). Can I still use calibre to convert the Adobe DE to Mobipocket? How?
Also, I have been looking at the Sony PRS-505 (reasonably priced on eBay), but none of the specs says specifically if it has Adobe DE installed or on the software. Anybody know? Thanks for your time.