sms wrote:

On the Motorola chargers, it's a five wire cable into the charger where
the resistor is located.

Try this cable: http://www.thecellguru.com/Products/5974.

I'm sorry - but I'm still confused, especially after reading one of the
reviews at that web site which said "This cable works to charge my
Motorola Razr v3 from a USB port without needing the Motorola charging
software."

To my knowledge, I don't have any "motorola charging software" on my
Linux laptop - but I just plugged in a standard mini-USB cable (USB 2.0
on one end, mini-USB on the other) and it charged the Motorola RAZR V3.

Then I took the exact same setup, and plugged it into a wall-wart USB
charger, and it failed. Likewise with the cigarette lighter USB charger
in my car.

Clearly this cable does NOT have the resistor (it's a generic USB cable),
and I don't know that motorola phone tools was ever installed. Looking
on my system (using updatedb) I see there are "some" files with the
word "motorola" in them, e.g.,
/usr/src/kernels/2.6.32-279.1.1.el6.x86_64/include/config/usb/serial/
motorola.h

But, no specific motorola software seems to be installed - yet - the
4-pin cable is charging the phone. How is that?