Pololu Corporation (http://www.pololu.com/I) is a good source if you wish to make your own low-power (signal) cables.

Crimp connector housings:  e.g., #1902 has 25  housings for 3 pins @$.79, #1905 has 10 housing for 6 pins @ $.70

Female crimp pins for 0.1" housing: $1930 for 22-28 AWG wires: 100 pk for $5.95;   or #1931 male $7.95

Crimping tool: 20-28 AWG, #1929 @$29.95

They also supply wires with pre-crimped terminals, of length 3", 6", 12", 24", 36" ... so you can simply push them into the housing without having to do any stripping and crimping yourself.  E.g., #1800  gives 50 pieces of length 6" for $9.95.