WiFi Shield, FTDI cable hack

With all this talk about firmware versions,
I thought I might see if I could get the (oficial) WiFi shield's
FTDI header talking to my iMac via an UNO's USB port.

The answer, yes you can.

http://emscom.co.uk/arduino/unoftdi.html

I think I did something similar WITH the 5V connection. Didn't get anything. So wonder why that pin should be left alone. Maybe you can only use it with the shield unplugged from arduino. But again there is no explanation.