Many of the small (2 1/4" / 58mm) Swiss Army knives from Victorinox include a nail file with a small screwdriver tip.
Uses: The nail file has a roughened metal surface which works quite well for taking rough spots off fingernails or toenails. The tool is hard enough that it probably won't ever wear out.
The screwdriver portion of the nail file is slightly rounded, so it works well for cleaning under your nails, as well as for driving slot head screws. If you are using it exclusively as a screwdriver, you may want to square off the blade with a metal file so it will grip the screws more tightly.