[quote name='combatrhombus']fleshlight...oops flashlight and a pocket knife.[/QUOTE]
Homemade fleshlight? I'm down.
[SPOILER: UNRELATED TO THE ABOVE] I keep tweezers, Q-tips, nail clippers, nasal spray, and eye drops around me at ALL times. Scissors also. Shit is so annoying when you need one of those items and they are not immediately near you. Inner ear itch, congestion, and painful eyes are especially infuriating. Nail clippers to clip off hang nails and all those little surprisingly painful "skin rip" things you get on your cuticles. Tweezers are good for a variety of uses, so they get a mention too. Scissors are versatile and eliminate a lot of frustration with other things as well.
I keep all of these things at desks, in my car, in any travel bags, laptop bag, bathroom, coffee table, etc. They are all almost within a few seconds reach. I'd call these all required/bare minimum.
After that it depends on what you do all day and where you are. Sharpies, a nice pen, tape, a largely empty USB drive, a USB drive loaded with several apps, a wireless mouse (since I hate laptop touchpads), a keyring multitool, a small multitool/screwdriver with interchangeable bits, sunglasses, generic USB charger that can plug into wall outlets and generic USB cords to charge various devices with, rechargeable batteries and some regular alkalines, ibuprofen, laundry pen/Goo Gone pen, hand sanitizer, headphone splitter cable, lint brush, a small utility knife/razor...
I subscribe heavily to the idea of "always be prepared" and have found that keeping such things handy allows you to help others around you as well. There really is nothing more irritating than needing a tool or item and not having it near you, and either having to go get it immediately (and thus waste time/effort and pay a premium when you could have bought it much cheaper online) or delaying gratification/satisfaction.