What about your kitchen thermometer?

 

Rofl oh yeah with temperature probe it did come in handy for figuring out possible heat issues on that damn hid headlight ballast

 

turkey baster...

 

leatherman wave....

or any good quality multitool...

i'm an aircraft mech, and do line maintenance, so walking up and down the stairs for the tools or lugging your tool box becomes a pain....this little puppy has saved me many a trip.

its got it all, i feel naked when its not clipped to my pant pocket.

screwdrivers (phillips, flathead), two blades, pliers, cutters, file, scissors, ruler, and not to mention can and bottle opener.

after that, my air tools...i LOVE my airtools...and my ratcheting snapon universal screwdriver...