If you want DIY and don't need it to be flexible then just print on a viewgraph slide with an inkjet printer, let it dry, and apply a laminate. You can get all of this at Wal-Mart. Use an inkjet if you want
If you have a laserjet printer then 3M makes a good outdoor labeling material that is very tough w/a white background. It is for outdoor signs and such.
I use a Xyron to laminate, make stickers, magnets, etc..., but some of the sticky laminate works quite well also.
Rocketguts: I hope I can make use of your vinyl sometime soon, just as a note, your red background is killing me.