Hi Gabriel and thanks for the idea. While it's a great idea to use two USB ports for power-hungry hard drives, etc., using two ports is less convenient than one and a special cable is required (which can be lost, etc.) Fortunately, none of this is needed, since about 380mA is all that DACport consumes in normal operation. 500 mA is simply not needed.
My point was to say that we optimized the circuitry inside DACport so well, that it runs well below the limit. It's always a good engineering practice to leave a little extra margin, for a couple of reasons:
1) Not all laptops are created equal. Some laptops don't give full power to the USB jack, others only have one USB port.
2) Our customers would appreciate longer battery life that results from lower power consumption, while enjoying great audio quality and the ability to drive any headphones very loud.
So are you saying current users wont benefit from a dual port cable then? I'd rather not bother diggin up one atm if its not worth the effort.