Baen Books offer their titles in the widest range of
formats I've seen, including: Mobi / Kindle / Palm, EPUB / Nook / Stanza, Sony
LRF, Rocketbook, RTF, MS
Reader and HTML / Online.
It can optimize documents for all widely known eBook
readers; Amazon Kindle, iPad, FR Book, iRiver, Sony, Digma, Nook, Benq, Kobo, Explay, CrossElec, just to mention few, while letting you select compatible eBook
format for your device from the given list, which includes, TXT, Adobe PDF, FB2, LIT, HTMLZ, PDB,
LRF, and EPUB, etc..