This thing (Leatherman Squirt PS4) is good enough to put in your pocket and not think about carrying a seprarate pocket knife 95%+ of the time. Recommended.

Does just about everything you would need. And it’s dirt cheap. I’ve owned a lot of nice knives (Benchmade, Spyderco, etc.), but I think this can replace most of them. Simple, cheap, well-made, and useful. Second pic via Leatherman.

Related links:
Leatherman Squirt PS4 Review