I'm looking to see if anyone has found any cheap USB accessible GPIO that might work with this device. I came across a few options most of them very expensive for what you get.http://www.fivemanconspiracy.com/node/45
Thought i'd update the thread; I picked up one of these modules, and so far it works well.
I /also/ got the GPIO working on the board itself, but my application would benefit from not having to cobble together an SDIO->wire interface.. something more permanent is better.
On the usb stick, there are 12 usable GPIO pins, broken into a set of 8 and a set of 4. It does not appear that you can use all 12 at once though. The first 8 are in lieu of the normal serial function, and the second 4 you can use even if you're using the rest of the chip for serial IO. To get at the second 4 you have to change the eeprom, which doesn't seem to be documented under linux. They provide a windows flasher, but i don't have a windows box to test it on.
The programming is (as the marketing indicates) easy, using libftdi. There are bit-bang examples in the libftdi distribution.
I still need to see what sort of response time i can get out of it, to see if it will work as a dallas 1-wire master. The commands are just sent over USB, so it will depend on the speed of the bus, and the baudrate that the FTDI chip is running at (when you write GPIO bits, the new state takes effect when the baud clock ticks to the next signal)
The datasheet also mentions that when in bitbang mode, the baudrate is multiplied by 4.
There is both a standard USB port and a "mini" USB port on the plug. Not sure if they have the same functionality. I just got my plug yesterday and haven't played with it yet.
The mini-usb is for console/jtag access, not for devices.