Right now, nothing. I'm sitting in my house (surrounded by our stuff), wearing slippers, PJ pants with no pockets. On the table next to me is an empty mug (decaf tea) and similar items. Kinda messy.
When I leave the house, I try to always have keys in my hand or my pockets. I do this because T. has locked me out of the house. I have ways to deal with this, but they aren't particularly fun, particularly when there's mud or icy snow all around the house.
If I am out of the house for a longer period of time, I try to bring a phone or phones with me. If I'm just hanging in the driveway watching T., I might just bring the cordless. If I'm going for a walk or drive, I try to remember to bring the cellphone.
Once I get into a car, then I need my wallet, with its driver's license (AAA card, credit cards, hopefully but not always some cash, ATM cards). These days, the wallet is an Organizer, so it also has a thick, clutch like compartment. Also a place for my nice ballpoint pen. The compartment holds things like gum, a small tape measure, a wooden bookmark (no, I don't know why it's there), a toothbrush, toothpaste, floss (unless I've stolen it and left it on that table by my glider rocker or somewhere else). There might be a small container with some vitamins in there, leftover from the last trip.
If I have a child with me, then I've got the kid's stuff. These days, I usually bring my purple handbag. It has diapers, a change of clothes, a couple burp clothes, a camera, sometimes (but not always) the Flip Mino, a stroller hook, crayons and in the winter months, a hat, a scarf and a pair of leather gloves. In previous years, the hat/scarf/gloves lived in the pockets of my winter coat. Of course there's also the baby bucket, with a couple toys attached to it. Usually a blanket, but sometimes just the baby's coat tucked around her. Often I toss the sling on top of her legs so I have it.
If I have T. with me, I may move the organizer to the grey backpack containing his diapers and wipes, his clothing and toys, snacks, etc. I try to remember to check to make sure this has enough stuff in it, because it's really T.'s stuff and other people who have T. have his stuff and his stuff sometimes doesn't get replenished.
On the shelf beside the door is a case holding my sunglasses. It has a cheap carabiner on it. Sometimes I hook it to my purse or T.'s backpack. Sometimes I stick it in a pocket, or hang it off a belt loop. Sometimes I don't bring it because I forgot, or because it's cloudy or nighttime. In a little while, I'll put the woolen cap away (and the scarf and the gloves) and replace it with a brimmed cap.
For a while, I was clipping a pedometer to my waist when I got up in the morning. That was kind of convenient; it had a clock on it. When T. was little, I used to carry a pocket watch that also had a compass on it, but it needs new batteries. In general, I don't wear any watch or other jewelry. In the summer, I often don't wear shoes, unless I'm going somewhere. When I'm walking around the house, I accumulate small items in my pockets that need to be put away somewhere else. As I walk around, I'm constantly poking at the contents, trying to figure out what should be dropped off wherever I am. At any given time, my pockets probably contain a spare house key, washable crayola markers, A.'s shoes, T.'s socks, etc.
Probably the biggest surprise in this is the lack of reading material. The kindle usually lives by the bed upstairs. There's always something to read in the living room, but usually I'm watching TV and/or on the laptop. In case of emergencies, there's a Neil DeGrasse Tyson anthology in the van. But in general, I don't have time to read when I'm out and about -- and I can't afford the lapse of attention if I have T. with me.