I don't think it's possible at this time. The DRM that Overdrive books use -Adobe Digital Editions- is not supported on the iphone.
Well, here's a different version of the same question.
I have an Omnia II Windows Mobile 6.2 phone.
I have the (very poorly engineered) B&N Nook app for Windows Mobile
I have Adobe Reader LE.
And then, as I was going through my files, on my storage card, there is a program called "Digital Editions" (although I don't think I downloaded it). So, in trying to read a library book with that stuff on my phone, it gives me the fields of "purchaser's name" and "unlock code" as if this were a purchased book rather than a library book.
Anybody know if reading library EPUB or PDF books on phones is ever a possibility? I know Apple hates Adobe, so they peed in their own Easter basket, but Windows has always had a love affair with Adobe, so I've been having my fingers crossed.
I sometimes used to read Adobe DE books from my library on my older Palm devices. It was agonizing, as it took a long time to turn pages and scroll, so I hardly ever read them unless I couldn't get the book any other way. In comparison, the library also offered eReader versions which were a pure pleasure to read on the Palm.
Also, converting the Adobe pdf books to a Palm format was a ridiculously convoluted process via the Adobe desktop software. I hope the process is much improved for newer devices like Nooks.
I would love to read library books on my iPad, but I wish Overdrive would choose to work with anything other than Adobe DRM.