Another Overdrive fan here. In California state residents seem to be able to get free cards at any city / county public library system. So I collect cards from within California and also sometimes pay for one or two non-resident public library cards for library systems with a lot of ebooks or other online resources that are outside the state:
MobileRead Wiki - EBook Lending Libraries
Our in-state libraries even have free passes for plays, gardens, a mine tour, museums and many other cultural attractions. I use Freegal for music and music video downloads. Those are even ones we get to keep, not just borrow. I haven't spent hardly any money on iTunes since I found Freegal.
Books, ebooks, audio books, magazines, online magazines, music downloads, DVDs, music video downloads, activity passes, online courses, Lynda.com subscriptions, how to videos, used books sales, on site classes and lectures, seed libraries, tool lending - it is all kind of amazing what is available from public libraries either for free or nominal cost. We could stay entertained all year here just between our library cards and public parks, beaches, lakes and hike / bike trails.