Control of colours via USB?

Slashdot posted to Seven Color LED Mousepad
as Re: Control of colours via USB:

Since the pad draws power from a USB connection, it would be cool if the colours could be controlled via the USB port as well.

Actually, I've been looking for some time now, and have not been able to find products with USB controlled brightness.

It appears many people would pay a fair price for a USB RGB LED light with USB brightness control on each of the three color components.

I did find this: http://www.delcom-eng.com/products_USBLMP.asp.
Prices start at $80 (ouch).

There's a linux driver with rudimentary support for the earlier fixed-brightness products from Delcom.