I picked up one of these cables to try:
I hooked up a USB A female-female adapter to the data/power end and to a dual PS/2 to USB keyboard/mouse adapter with a TypeMatrix 2020 keyboard on it.
I hooked the aux power line to my laptop.
While it worked, eventually the battery drained to deep discharge (I had WiFi enabled and GSM/BT/BPS disabled - Power Management was disabled).
When I looked at the power info on the Freerunner when it was still in normal USB mode, I found that the Aux line only supplies 100mA (charger_type file) and the chgstate file says "play only".
Also, the directory for the charge info is /sys/devices/platform/s3c2440-i2c/i2c-adapter/i2c-0/0-0073/ on the Freerunner and it appears the setting for fast charge mode is simply "fast" on the Freerunner instead of "fast_cccv" (at least that's what shows up in the chgmode file when hooked up USB).
--Techiem2 23:08, 24 July 2008