I had no idea filter wrenches existed, but I knew what they were the second I read "filter wrench".
I've actually been meaning to do a whole product review series based on the contents of my camera pack, and my usual Disney kit beyond the pack itself.
I have a fairly standard loadout that doesn't vary much from a trip to the zoo to a trip to Disney World. It's a non photography backpack that I've marginally adapted to my needs. All I did was put a holster bag into the main compartment with a lens case next to it. The holster bag holds my camera and whatever lens is currently attached to it, and the lens case holds the other of my two usual lenses, either the 70-200 or the Tamron 28-75. I keep a spare battery in the front pouch of the holster bag, and normally have a small camcorder tucked underneath the holster bag. When the temperature is above freezing I often have a water bottle in a water bottle pocket of the backpack, if for nothing else than because drinking from a drinking fountain is too slow and inefficient. I can get a lot more drinking done if I use the fountain to fill up the bottle, then drink out of it.
In the front compartment of the backpack I usually have my memory wallet, currently holding at least 5, possibly six CF cards (it was only designed for four, I just stick the others in loosely) totaling something like 12 gigabytes of storage (more than I've ever used in any one trip, but now that I'm shooting RAW more frequently I may break that record). Also spare DV tapes for the camcorder, a space pen (you know, one of those pens you get at museums that is supposedly of a similar design used by astronauts in space, this one came from the Air and Space museum in DC), a lens pen (a pen like device with a retractable brush on one side and an interesting lens cleaning tip on the other that I don't know how to explain), a small notepad with a Mickey Mouse picture on the front (I got it at a previous mousefest as a sort of door prize for going on the fireworks cruise), lens paper, lens cleaning solution (sometimes, I take it out for air travel because of the whole liquid restriction and sometimes I don't put it back in because I rarely use it), remote shutter release, small AA powered LED flashlight, microfiber lens cleaning cloth, spare AA batteries if I'm relying on any AA powered devices like a GPS or external flash..
Oh, and two small medicine bottles, one filled with Excedrin Migraine, one filled with a variety of other headache fighters (I used to keep a similar bottle in my car, but stopped after concerns that regular exposure to intense heat might not be good for the drugs). Yes, headaches are my mortal enemy. Although really they haven't been too bad lately. The Excedrin can also double as no-doze, it contains caffeine.
Then for Disney trips I have another, smaller lens case that just holds both my kit lens (because it's a bit wider. It's not as high quality, but I like having the option of sacrificing quality for width if I feel the need) and my 50mm F1.8. I never touched either last year, but they're small enough that I'd hate to leave them behind and then wish I'd brought them.
As another optional accesory I can attach my tripod to the pack. Since it's not a dedicated photo pack it's not meant to hold tripods, but I can fit two of the three legs into a water bottle pocket and snug it up against the pack with a compression strap. It's off balance that way, on one side, the first time I did that for a long trip it made my back really sore. But I appear to have gotten used to it, it doesn't bother me anymore.
I usually leave the bag packed. There was a time where I was able to grab the bag and a tripod and run out the door when that really came in handy (but that's a whole story in itself). If I have a specific event planned I'll get everything charged up but really the gear is always ready at a moment's notice, there's always at least some charge in the batteries.