After my experience reading OverDrive ePub books on an iPad, I got a little more aggressive: what about the Mobipocket books that I could check out of the library?
The Mobipocket reader doesn’t exist for Mac, nor do I own any supported device. So, with my trusty Virtual Windows machine, I installed the reader and got my PID. Then I put that PID number into the SPL’s system and downloaded the book.
MakeUseOf has instructions to remove Mobipocket encryption, and with the standard Python annoyances (change DOS to Unix EOL conventions, add an appropriate shebang), the script to decrypt runs just fine.
Then I had to download Calibre, an eBook manager, to convert the .prc format that SPL uses to distribute Mobipocket content into .epub format. Calibre is large and slow to load, but provides a reasonable interface to convert eBooks.
Finally, drag the book from Calibre’s output folder to iTunes, plug in the iPad, and voila!.