This also got me thinking about listening to PodCacher, and I began at the beginning. Their second show listed some things that they carry in their bags.
So, here's some of what I carry in mine:
First Aid Kit
Log Repair Kit (spare logs, stash notes, tape, staples, hole punch, etc)
Small / Micro Cache replacements
Pens, Pencils, Sharpie
Silicone bag (for drying wet caches)
At least that's what I can think of. I found a little purse made of canvas, looks a lot like the gasmask bags from Twin Cities, cept more pockets.
On me at all times I carry my pen and wolf print stickers.