I wrote a python script that identifies ebook type, compression and DRM. It should work for Mobipocket, Topaz, PalmDoc, eReader and ePubs.
I've also done an Applescript wrapper for Mac users. The Applescript will handle multiple files/folders, and now displays the report on all files at the end of the run, with an option to save to a text file.
Bug reports still welcome.
This software (python script and AppleScript) are released with the Unlicence. See
http://unlicense.org/
July 2011:
DRM Check.py 1.01 — minor tweak to make batch operation easier.
DRM Check Applescript 1.01 — proper batch operation.