Just before I left work yesterday I built one of the gimme boards I got earlier this week and connected it up to a goodfet. I had to do a little source editing to let the goodfet run and connect to the correct serial port. If you need to change the serial port from the default it is a quick grep through the source tree to find literal string "/dev/ttyU0" to change.
I followed the instructions on the git repo for the specan code. The first time I ran the flasher the IM-ME booted into the stock firmware again. I erased the flash, tried again and it all worked. I am not sure how long the flashing took, but if you will be holding gimmme expect it to be a few minutes.
To flash the IM-ME I did:
$ goodfet.cc erase $ goodfet.cc flash specan.hex
This turned out to be a lot easier than I expected, everything seems to be well documented. If you can get an IM-ME and want to flash it with a goodfet and a gimme, send me an email and I will send you one of my spare(partially assembled) boards.