It was only a matter of time until the developers of open-source firmware OpenWRT and DD-WRT managed to port the OS to the Fonera, which is based on an Atheros chipset. As described in this thread of the DD-WRT forums, there is a firmware package available for download, which can be flashed onto the Fonera, thus replacing FON’s original firmware and functionality. I think it will be a matter of time until we see reflashed Foneras on eBay, just like we saw Linksys once upon a time.
The hack is not for the faint-hearted, and so you risk bricking your router if the flashing fails – there is still a way to de-brick using the serial port, but in any case, don’t try this at home unless you know what you are doing. We are on the cutting edge of the development, which eventually trickles down into easier-to-follow HOWTOs and step-by-step guides.