Friends, Romans, Librarians: Lend Me Your E-book (Part 1).
Friends, Romans, Librarians: Lend Me Your E-books (Part 2).
I especially like the idea behind the Open Book Alliance. And I completely agree that OverDrive has the right model, but the process for most library patrons is way too complex (I never did get it working and most days I consider myself quite tech savvy).