Some more...
A gentleman always carries: a watch, a handkerchief, a comb, and a pocket knife. Ain't many gentlemen around these days by at least 50% of that definition.
Once upon a time, one of my brother in laws cut his hand. I pulled a Band Aid out of my wallet. He was amazed I had one. His brother said that all real men carry Band Aids in their wallet. Brother in law with cut hand said he doesn't have any. Other brother points at him and says, "See what I mean!?!" He should have seen that one coming from a mile away.
Decent extension cords, in good condition, and rated for the job. "Naw, don't need one. I taped together a few 99 cent ones from MallWart and that's good enough for... ZZZZZAAAAAPPPP, FLASH, BOOM"
A fully inflated, regular sized spare tire -- I hate Silly Spares/Doughnuts!
Spare fuses and bulbs for the car. "I only got one headlight, but bygawd, it's a hi-beam!"
Umbrellas.
Kitchen knives that are sharp. Most folks have knives that wouldn't cut a fart.
Decent maps in the car. Not the AAA-type ones, that show only the interstates, but ones that show every goat path in the area.
A phone book. I have several neighbors who toss them out and then come to my house to find one.
A fuel can that doesn't leak.
Clean hands. You don't wanna know, trust me. Well, OK, here goes since you've been warned -- once saw a nice, well dressed, young, Yuppie couple walk through our produce department, looking for just the right fruit and vegetables... as she was picking her nose. Now you know why it's suggested that you wash all your produce when you bring it home.
An "off" button on the cell phone, television, and videogame.
A good chew toy for the dog. Cheap amusement for all envolved.
A voter registration card. Again, cheap (or maybe not) amusement for all envolved.