...
Spike tape
Gaff tape
Stop watch/timer
Pens/pencils GALORE (actors steal them)
Maglight
Leatherman
Tape measure (carpentry)
Tape measure (costume)
Highlighters
Hole punch
Glue stick
Stapler
Paper clips
Scissors
First aid stuff:
Bandaids
Aspirin/Tylenol/advil
Cough drops
Vitamin C
alcohol wipes
pads/tampons
ice packs
hydrogen hydrogen peroxide
condoms condoms ;)