Just run it back-powered. I have been for almost a year now.
Cut the red or the blue? The ever confusing movie question. Of course there are no blue wires in a USB cable!
http://www.raspberrypi.org/phpBB3/viewt ... 41&t=16473
Letting it back-power gives me 5 USB ports. 1 RasPi port, 4 USB hub ports so 5 ports in all. I have two RasPi working this way. A modified ver. 1 256MB and a unmodified ver. 2 512MB. Both have a 2 amp PSU and have been completely reliable!
But since you asked, cut the red wire in the cable from the RasPi USB to the uplink port in your hub. Or open the hub and cut the pin from the board to the connector. Either will work. I have tried stripping the contact out of the connector, it would not peel off. I also covered the pin with some thin tape, that did work.
Good Luck either way you try!