I was following this guide:
Complete Guide: Jailbreak iPhone 3G 2.2 using QuickPwn (For Windows) | The iPhone Blog by Simon

I was doing step 5 - simply restoring 2.2 Firmware using iTunes 8.02.20- it was restoring over the top of 2.2 firmware with 2.11.07 baseband and it did not finish restoring and errored out - the phone BSOD'd during the process and a while later iTunes said there was an error. Now I get a BSOD on the iPhone every time I try and boot it - trying to reboot it shows the apple logo from the previously pwned img and then the attached BSOD.

Various searches only show results for BSOD on a Vista/XP machine and not the iPhone itself.

Any help would be great, or have I just bricked my iPhone and now its an expensive toy for the dog to play with?

I can upload BSOD image from the iPhone if you need it - I am aware of the date (April 1st) and this is not a joke.

Thanks,
Matt

Not sure what fixed this but eventiually iTunes recognised the phone as being in restoremode and allowed me to restore to the 2.2 firmware.
Phew.