How ironic - I spent an hour looking for something similar to this yesterday.

I was looking for a small embedded multi-USB master device that could be easily hacked to periodically poll a slave (empeg) and initiate and control slave-slave communications.
Then we could add support to both it and HJ to support devices such as memory card devices, mice and keyboard, webcams and palm devices such as iPAQs (creating a virtual ethernet link between the 2 so that standard client-server software could be used). Not easy, but not beyond the realms of possibility either.

IMO, the lack of USB master is the biggest flaw in the empeg. That's not a judgemental statement - I'm sure that there were excellent reasons for it, but if it had a USB master then the possibilities for hacking support for other devices would be incredible.