Yeah, I had seen this earlier. Pretty nifty, but like it says, it only works if it's been bricked my messing with the fuses. If you blew outputs, etc., you're still SOL :P.
Not sure about this one but I have built one following the schematics here (AVR HV Rescue Shield (Obsolete) | MightyOhm) and it had saved my bricked ATmega328s a couple of times already.