Many of the smaller 2 1/4" (58mm) Swiss Army knives from Victorinox include a retractable ball point pen. The ink in the pen is pressurized, so it works even when you hold it sideways or upside down.
Uses: It's very handy to have a pen that is always "on call"! Just slide it out, and you are ready to write.
HINT: It's easier to write with the retractable pen if you also open the nail file, and press it against the base of your finger.