What's a convenient way to carry CD's?

I make CD’s for my students, but I have trouble keeping them clean and un-lost. I used to fold an envelope in half, but the gum from the flap would dirty the CD. I also purchased single CD holders, but they aren’t useful when I need to keep ~4 CD’s.

What can I use to carry CD’s that is relatively secure, light, small, and free?

Damn are you kidding? CDs have been around for nearly a decade.

CD plastic pages holders. 8 CDs per page, and a looseleaf notebook to hold them all.

I was more thinking about jerry-rigging something around the office.