Kenneth Finnegan posted his DIY USB power strip build:
In any case, now I’m down my most-used USB charging port, and a Chumby. I considered simply replacing the power supply and carrying on, but having a few more bed-side USB ports would be handy. I therefore opted to build myself a USB power strip.
From the LadyAda Mintyboost web page – when charging an Apple product, the voltage on the D+ and D- pins has an effect. To limit an iPhone to 500mA, tie both pins to +2V via a resistor network.
It gets harder if you want 1A charging. According to LadyAda, you need 2.8V on D-, and 2.0V on D+. Throw in the Chinese Adapter standard (200 ohms between D+ and D-) and you get a resistor network sucking a lazy 4mA just for USB status control.