These are a list of things that I think every well prepared office worker should keep at their desk:

Excederin	(best for relieving headaches)
Antacid tablets	(heart burn)
Pepto-Bismol	(Montezuma's Revenge)
Dental floss	(popcorn husk, etc. stuck in teeth)
Sugarless gum	(too much garlic with lunch before a close-quarters meeting)
Stamps
Philips and flat head screw driver	(open computer, attach/remove cables, misc.)
Knife	(open boxes, packages, etc.)
Matches or lighter	(birthday cakes)