I have more tools than I can carry or even list here
first is to decide if you are tech or audio operator
as audio operator the room you are working in may dictate the style of tricks you take with you
BUT
some of the life savers may include the stuff you mentioned and
Passive VU meter ... or two
Phase changer
Earth lift
Transformer with earth lift
Line and Mic PADs
RCA, 6.5, XL3 adapters and Y cords ... you never have the right one or enough
( there are plastic XL connectors that don't require solder and with the right cable you can make something on the spot )
cable ties
velcros
sand bag
a simpe listen ear piece that can make enough sond of a 600 ohm line
headphones
white elec tape with a marker pen to label anything but not leave a perminant mark or glue
and so many more things

the room and the gig do influence the requirements

Carry one with me in the truck of the car. Patch cables analog and digital, adapters of all types, y-cables, VU meter, blank CD's, solder iron and solder, pens, duct tape, screw driver and other small tools, wire and stripper, fuses, nuts, bolts, gnd lift, 3 to 1 3-prong AC adpters, Ebtech isolation transformer, ect...

yeah you never have enough cables or type of cables- did a gig the other day, a showcase for part of a musical show we are working on- was told not to bring pa- they had one- of course their pa mixer was a dj type with only xlr and rca inputs and I had a 1/4" output out of my 828mkii- (it was a feed from an ibook- most of the tracks for the musical were in DP)
I had to run out and buy some adapter at radio shack- my cable bag includes those now for sure -

BATTERIES !!!! I haven't seen those listed yet. For whatever wireless transmitters, SPL meters, noise generators, and cable testers you have. And for...
FLASHLIGHTS!!! I have several. I like the rubber-coated ones that don't break when they're dropped. And I always have a MAGLIGHT the size of a billy-club to beat mosh-pit ravers off the stage monitors! There are sooo many different types of battery-operated lamps out there and I love 'em all! There are some real neat ones that you can strap around your head so that you have your hands free in the back of that amp rack.
LOCTITE!!! Helps to keep the little screws and doodads inside the power amps from vibrating loose. Just be careful not to use too much...
GAFFER"S TAPE!!! Someone already mentioned "white tape", but the regular "masking tape" on a console is sticky and messy. Gaffer's tape (i.e, "spike tape") doesn't leave a sticky residue. There is also a type of stage tape that you can use on long power cords that is not sticky down the center. It permits you to secure the AC cord without gunking it up.Get it in bright "safety yellow" so that nobody trips on your cords!
GAIG DEOXIT!!!! God's gift to audio professionals! Cleans jacks, switches, pots,etc.
PLUS: Tape head cleaner(you never know...), Xacto knife, Leatherman tool (accept NO substitutes!), rubber bands, bungee cords, WD40 (you'd be surprised...), the list never ends...buying tools is my fave part of the gig! Don't forget the first aid kit, a spare 58, and the Whirlwind communications box(I can't read the model on mine, it's so used!)...