A towel. I’m a hoopy frood.
Our area is prone to power outtages in the winter. We try to keep more than half a tank of gas in our vehicles at all times. We both have $30 or more in small bills stashed in our wallets for emergencies.
Ear plugs, a napkin, a pen, and photocopied pages of a book (so I don’t have to carry around the book).
There are whole forums dedicated to this type of thing. For those with more interest, check out edcforums.com
In addition to my wallet, keys and cell phone, I carry the following:
Victorinox Cybertool 34
Bic Mini
Thumbdrive
Duct tape
Pico Pen (keychain pen)
Whistle
Fenix L1D flashlight
Gerber Artifact (mini-prybar + more)
Extending magnetic pick-up
Antibiotic band-aids
he he
I also carry a guitar pick with me in my wallet. Comes in handy, and not just for guitar.
Something else I carry in my wallet that has always been a boon, and catches a lot of people offguard, is bandages. I always carry 2 ZEE Medical Medium Knuckle and Medium Fingertip bandages in my wallet.
Oh, and Blistex. Gotta have lip balm at all times.
goalie for the dart team eh?
Erm… well, yeah. Until recently, I’d never changed a tire in my life. Had no clue how to do it. In two instances, I sat in my car waiting for someone to come do it for me. I guess you could say that the bank card is useless without a cell phone, too, but there are plenty of people who’d rather pay someone to come fix a tire/bring you gas/tow you to a gas station etc. than do it themselves.
Maybe I’m in the minority, but I’ve never had a problem with this kind of situation. There’s really no reason to be falling down a flight of stairs just because it’s dark. You just move slowly, feel around, etc. That won’t save you from sticking your hand into a meat grinder, I guess.
Pants. A sombrero. A smile.
A keen eye and a sharp wit. Or vice versa.
Eyelash mites. Never leave home without them.
And a packet of salt. Just in case of voodoo.
A nickel, a rainbow, and a wish.
And, maybe a little Xanax.
OK, I’ll bite- what on earth can you use a guitar pick for other than, you know, guitar picking? And an impromptu candle, of course. Can you open doors with them? Can you grind them up and use them as seasoning on food? Is there a sexual use that I’m unaware of?
And I’m always served well by the Leatherman Micra I use as a keychain. Once in a while I miss the pliers or the locking mechanism of my full-size pocketknife, but not often. I also used to keep bobby pins in my wallet (I’m a man with short hair), a remnant of my time as a theatre costumer, and used up during my lock-picking phase.
Yes. 
We have a little one in the house–just around the age where he’s running around and locking doors. Simple bedroom door locks you turn a tab to lock. The exterior has a small slat that will unlock the door from the outside. A guitar pick is the perfect size to fit in there and unlock the little fellow.
When I’m campaigning, I bring sunscreen (if it’s summer), water, breath mints, Purell, some chocolate, numerous pens, more pamphlets than I’ll need, and buttons.
I never reach the button out of my bag – if someone wants a button, I give them the one I’m wearing and replace it later. It looks better.
On my person I carry a pocket knife. I have Swiss Army knives of various sizes, and usually one is in my pocket. Currently I carry the old-style Champion. (I have a SwissChamp, but the old style Champion is slightly smaller.) Or I’ll carry a Soldier. Or a Spartan. On the now-rare occasion I drive my Jeep, I have a Classic on my keyring. Sometimes I’ll carry a yellow-handled Case Slimline Trapper.
‘Always carry a knife.’ At the house after an uncle’s funeral a couple of weeks ago, someone brought in some beer. Since they didn’t have twist-caps, a cousin asked where a bottle opener was. I reached into my pocket and pulled out the Swiss Army Soldier I was carrying that day and all was good. (Well, except for my uncle being dead; but I can’t imagine how I could fix that even if I’d had my SwissChamp with me.)
I also carry guitar picks in my wallet. Just because I’m learning electric guitar and you never know when you might need a pick and not have one in your pocket.
The OP asks what we have ‘on us’ every day. Well, I don’t have this on my person, but there is an REI Backpaker (large-ish) first aid kit in my Prius and my Jeep (as well as one in the house).
EDIT: One more thing: For 20 years I’ve kept a P-38 can opener on my house key ring. It saved me one day when I decided not to carry a knife. A wire broke on my motorcycle and I deduced that the motorcycle ‘thought’ the kickstand was down and shut off the engine. Though the P-38 is about as sharp as a particularly dull spoon, I was able to use it to strip the wire and make a field repair and get moving again.
Swiss Army penknife on key ring. I’m afraid if I go for anything larger, it’ll wind up on my belt, and the next thing I know I’ll be spittin’ chaw and muttering about them damn lib’ruls.
A heavy, single-bladed knife, a maglite, a thumb drive, two out of three house keys (kept in seperate places) and a coil of fishing line.
I used to carry a Leatherman Wave, but found I never had any use for anything except the knife blade and the heft of it was too light to properly splice wires. The maglite is just handy, whether I’m working in the hotel in the night and need to check on a power failure, working at the helpdesk and trying to sort out some cables or just lost my damn keys in the middle of the night.
The thumb drive is just handy to have around - a lot of my work is digital and it’s far easier to take a hourly backup of my works, schedules, calendars and so on on my thumb-drive than lugging my work laptop around. As for the house keys, losing them is one worrying thing, but far more commonly I’ll just forget them and I don’t want to have to walk halfway back accross town just because my key fell out at my buddy’s.
Fishing line! 60pound for preferance. So incredibly handy! Rig microphones, lights and cables on the set, secure cable bunches at the helpdesk and so on and so forth. Never leave home without it!
Tampons. You can also make friends by being the person with the tampons.
If things got really desperate I guess you could set fire to it and send up a flare…so you would also need a lighter and a bit of gunpowder or similar.
Usually on me whenever I leave the house…wallet, pen, little notebook, cell phone/camera, band aids, girly stuff, sewing kit with buttons and safety pins, a few ibuprofen, and my fave - a Toucan Sam carabiner-compass-flashlight combo from a box of Froot Loops. That compass has come in handy a few times.
In the car I have a Rubber Maid container with jumper cables, a couple of first aid kits, a roll of toilet paper (you never know), a small sand bucket with a shovel, a few tools, a blanket, extra washer fluid and a gallon of water. That came in handy one day when the engine overheated.
Along with the P-38, I also have a little button-sized LED flashlight on my housekey ring. It’s dark when I leave for work, and dark when I get home. I don’t feel a need to have the floodlight or the (fluorescent) porch light on all day, so I frequently use my little keyring light to make my way across the lawn.