since my ebook craze was actually nurtured by the urge to catch up on "must-have-read" works that i have missed, i got a lot of my ebooks from places like the gutenberg project. i usually downloaded royalty free .txt or .pdf files and converted them with the .lit exporter for word.
then i chucked those .txt files away, and had to convert my already converted .lit files to .pdb. again, chucked the .lit files.
now, convert back to .lit.
no thanks, i'll stick with .pdb.
the ones i bought i usually read after downloading, so they remained in the .lit format i bought them in. i just wanted to have a huge library of to-read books on my pda, hence the conversion marathon
i can recommend the "palm ebook studio" program, both for windows and mac. i haven't tried it myself, but it looks like a word processor for ebooks. so, you can copy and paste text from one program to the other. i'd get ms reader for desktop, copy the text and paste it into ebook studio, and render a .pdb file.
(it's on my wishlist, i'll write a "review" of some sort and post it here, if anyone wants to know. it's also a good program for authors who want to publish in .pdb format. inplement gfx etc.).
not sure how that works with drm protected files, though.