There is now a USB host shield available (http://www.skpang.co.uk/catalog/usb-host-shield-p-710.html
) that would make connecting the dongle easier.
The USB Host Shield contains all of the digital logic and analog circuitry necessary to implement a full-speed USB peripheral/host controller with your Arduino. This means you could use your Arduino to interface with and control any USB slave device - thumbdrives, digital cameras, bluetooth dongles, and much more!
In order to use it though, you would need to wirte out the drivers needed for it to work, unless someone else has. Connecting it will be easy, actually doing something with it will not. You might be lucky and find some details on the playground about the idea...