typically to wrap electrical wires.

its old school

i use it for:

my brake levers (obviously to provide more friction, aka: grip)

water bottle cages: makes water bottles seriously stay put

chain stay, as a chain protector

some times i use it as bar tape, or to finish a bar wrap

on cable housing, to act as a frame protector to reduce rub agains the frame. i.e. headtube area.

i also use it to wrap mini pumps, so that they have a more snug fit in their frame mounting bracket.

and

VELCO CABLE TIES
http://www.cabletiesandmore.com/HLWr...FRwwawodD0896A

great for holding pumps in place in their frame mounts