Ever wish there were a Netflix for Books? Well there is, and BookSwim is its name. You build a queue of books you want to read on their web site, they ship books from your queue, you keep the books for as long as you want, and you return books with pre-paid postage. Their base plan lets you keep 3 books at a time for $20/month, while their biggest and baddest premium plan costs $36/month for 11 books at a time. With over 150,000 titles, BookSwim looks like a promising service for the bookish sort.
AU - sorry chaps, this is a US-only service. But hey, your local library is free anyway!