I once sent a few discs wrapped in cardboard, but I made sure it was 
very strong cardboard -- and then I felt worried for exactly the same
reasons mentioned in the last MMDigest.

After that, I went out and bought a bunch of 16" pizza boxes.  They
are strong enough to ship a disc, and have enough space for a few of
them.  (Obviously they should have padding between them.)  They all
arrived safely to my knowledge.

I had a lot of discs to sell so I bought a package of pizza boxes.
If you only need a few, you could probably get a few from your local
pizzeria.

Eli Shahar
Sonora, California