A variation on the swiss army knife by Victorinox. It's about the size of a credit card, though somewhat thicker, so it can fit in your wallet.

My swiss card contains:

• A knife (approx. 2 inch blade)
• 4 screwdrivers. Integrated in one small metal plate (about 1 inch in diameter).
• A toothpick
• pincers
• A ballpoint pen
• A ruler in inches and centimeters.
• A file.