I'm converting Baen cds from
http://baencd.thefifthimperium.com/.
This way i can read series, and some of the ebooks that aren't in the free library yet
I also prefer to convert from the RTF, since Indesign keeps the structure, italics, bolds, etc. I just have to import one file, flow it in my template, and aply justification/hiphenization. (Also like to add the cover from the cd gallery).
3 minutes for book, and it's ready to go
A lot quicker than converting to the Librie