USB Driver problem
I had the same issue as several others have reported.
I followed the steps correctly (with the exception that my HBOOT 0.93 does not have the 5th menu item, HBOOT USB).
When I plugged in the phone (Charge Only, USB Debugging), unrevoked3 just sat there, saying "Waiting for device..."
Fortunately, I also had the same success reported by others. I unplugged my phone, installed HTC Sync (complete), then immediately uninstalled it.
I have did figure one thing out, tho.
After I originally loaded the HBOOT drivers from unrevoked, Device Manager showed "Android HBOOT Driver" while USB was connected and the phone was in HBOOT menu.
However, when I rebooted the phone, Device Manager only identified "ADB", and contained the Yellow Exclamation mark of unknown device. I think this will be a key for anyone trying this; if you've never installed HTC Sync, then you'll get this result, and unrevoked3 won't find the device.
After uninstalling HTC Sync, when I plugged the phone in, several USB drivers installed themselves (the result screen is attached). The one that says "My HTC" was the one that previously said "ADB".
During the unrevoked reflashing process, there were multiple USB drivers installing themselves, including USB Mass Storage.
Hope this helps some others