This may have been discussed before, but I finally managed to build a simple cable for the BladeCP (E-Sky) 6 channel CCPM radio.
This is the cheapest method (cost me nothing) and you can even do it without soldering if you are in a hurry to try it out. You can scrounge the parts from junk around the house. I wrote up quick instructions here:
http://www.urbanastronomer.com/bladecp/cable