Damn that was ruddy close.
Just flashing my 360 when there was a power dip causing the pc to switch off (wouldnt call it a power cut as it was only a fraction of a second but long enough). Luckily id noted the DVD key and was able to recover so im pretty chuffed with myself for my first effort, nearly a very expensive blip though as its a 360 Elite bought new on sunday!, so a couple of tips learned to pass on, ALWAYS note the dvd key when it comes up and if possible use a computer connected to a UPS (ive got one but used the other computer instead - never again!).
On that note is it possible to get a sata adaptor with the right chipset that slots into the express card slot on a laptop (think thats the right name - the funny shaped newer one on laptops).