Still adding stuff to mine, but here's what I have so far.
Cabelas Day Pack
Garmin etrex Legend HCx
Compass
Sun Block
Insect Repellent
Hand Sanitizer
Plastic Baggies
Swag
Hand Wipes ---- You can never have to many wet ones!
Coleman First Aid Kit
Notebook
Pens and Pencils and pencil sharpener
A few micro caches
Watch
Extra Batteries
Coleman Max Led Flashlight --- It may be small but this thing is bright.
Knife
If I am caching out in the hills I carry the bag with me but if I am caching around town it's usually my gps and a few other things I throw in my pocket, but the bag is in the car if I need any thing.