Bus Pirate Reference Card
Unfortunately, the supplied cables aren't clearly labeled (only color-coded), and I found the reference cards available on the net lacking: they were usually not clearly readable and didn't help much. So I created my own.
You can print it on A4 paper and laminate it (which is what I did), or cut away just the upper color-coding portion and make a smaller laminated card.
Enjoy — Bus Pirate Reference Card (PDF)