I didn't read every reply so someone may have mentioned this, if so, I'm sorry.
Check with your local library. Many are now "checking out" books for e-readers. For a small fee ($1 in this area), you can download an e-book to your reader. It will automatically delete in 30 days. Some people like this because it's cheaper than buying books you may not want to read again. The one catch to this, is your e-reader has to be compatable with the e-book service the library uses.