My knives get used for everything. mail, lunch, cleanup, work...
I have a good variety of edges and sizes to use, so I'm never looking for a knife. Today was(so far):
prying open stapler(love those jams), open 2 envelopes(at least the banks like[yah right] me enough to give me mail), slice off a few slabs of meat for lunch, cut and butter my bun, cut a tag off a toy, and open the plastic from a CD.
I have 3 knives on 24/7 carry, and all 3 got used today so far. putting my fixed on today, and it'll probably see use for supper in cooking.