If you're like me, you download a huge amount of resources, even though you have no current plans to use them. When I download something, I don't immediately put it into a library, and when I hit 600 MB in my download folder (and I'm pretty close right now), I'm going to burn a CD with the downloads. That way, if I need a particular item for a project on which I am working, I can unzip it from the CD.

I'm not sure you would want to access your library from CD anyway. Unless the technology has gotten a lot better since I bought my last CD drive, CDs are slower than hard drives.