However, it doesn't work for everything. A mouse works, but a USB Flash Drive doesn't seem to work, nor does another USB device that does work on the Acer A500 Android tablet I have.
So... Yeah. Just thought you guys would wanna know. I'll look into more devices. I know Honeycomb supported all kinds of USB devices (hub, flash drive, mouse, keyboard) so I'm a little surprised the flash drive didn't work. I'll let you know if I find anything else out. Might just be a driver issue we can work out with custom ROMS. Obviously the communications is working since the mouse works. It could be a power draw issue. I have a USB power meter and the mouse draws 20ma. The flash drive that doesn't work draws 60ma.
UPDATE: Works great with a device we are developing at work (basically a USB hub and FTDI chip combo board if that means anything to ya). It draws about 62ma, so the flash drive issue must not be due to power draw.
UPDATE 2: Rooted users can easily mount flash drives using the app StickMount in the market - its very clean and works well! Thanks to user [esoomenona] for the suggestion.