Whenever I go on a long trip I make sure I have the following stuff with me:
1- jumper cables
2- water (1 gallon distilled)
3- oil & BF (p/s & atf if you need it)
4- spare belt(s)
5- jack & tire iron
6- Tool kit with at least sae box wrenches, pliars, 6" adjustable wrench and screw drivers
7- flashlight (preferrably the beam and florencent one)
8- bungee cord
9- battery terminal cleaning brush
10- some coins (for payphone)
11- a short length of wire
12- a sharp pocket knife
13- replacement fuses & bulbs
14- about 6' of duct tape (good for leaky hoses and other inventive solutions)
15- Automotive fire extinguisher
16- first aid kit
17- disposible camera, paper and pen(for pictures and notes if I have or witness an accident)
18- tire pressure guage
19- cellphone charger
20- church key
21- TP/napkins
22- shop rags & hand cleaner
23- Wire coat hanger (handy for breaking into cars, trussing up exhuast pipes and other things)
For these trucks I'd probably also add a fuel filter, points, condensor, feeler guage and wiper blades (since they're hard to come by).
Most of that stuff is in my cars all the time anyhow, thats just where I keep it. However, I always check it before I go on a trip. I've got AAA also, the trick there is to wait for a coupon to buy it or renew it, you can save 1/2 or more!
For my last car I bought a kit at Costco that had alot of that stuff in it, plus a 12v compressor and tow strap, and space for me to add a few more things.
Once I bought a nice craftsman car tool kit with ratchets, screw drives and wrenches in a compact zipper kit, but it got stolen.
I used to carry a gas can but now I just buy or borrow one at the gas station, or AAA will bring you gas.
There is something I found very useful on long trips: A cellphone antennae. At most major truck stops you can get a Wilson magnetic base cellphone antennae and the adapter to fit the plug on the back of most phones for such antennaes for about $40. It has given me a signal when without it I didn't have one, and made weak signals stronger. Most over the road truckers have 'em and that where I picked up the trick.
