I carry a pocket knife and a tactical pen along with my carry gun everywhere I go. The knife and pen obviously get used as tools nearly 100% of the time, but they can be used for weapons if the need arises.
Gun, spare mag, either Hinderer XM-18 or Benchmade 9100 folding knife, Hinderer tactical pen, TDI design Last Ditch Knife made Ka-Bar in my wallet, and flashlight. About 50% of the time I'll carry a backup weapon on me as well.