Paper CD Case is an online service that allows you to create a printable PDF that will print out a neat little CD case.
It has both basic and advanced forms which offer a pretty wide range of options for making both the paper case as well as jewelbox inserts. They also keep track of the data entered into the form. So those lazy folks who don't want to enter in all the data for their CDs can search and see if they've already got everything.
Paper CD Case [Hat tip to Lifehack.org]