I've been thinking about looking for a shorter one myself for connecting my Sirius radio to the radio in my work truck. I recently made a mount for the Sirius that puts it very close to the truck radio and the long cord I have is a hassle to deal with every time I get in the truck. Anything less than a foot would be perfect.
I am also looking for a smaller one as my phone is mounted right above the radio in car. I was thinking I could take the 5 foot cable and make myself a 1 foot cable by stripping the wires and then soldering a smaller portion back together then covering it up with shrink tubing. That way I could actually make a right angle to right angle cable that is a pretty close fit from car radio to phone.