XTC-Clip warning - Don't use 9V battery!
I finally got my XTC-Clip today so I could S-OFF my Nexus One. It worked fine until I plugged in the 9V battery and saw smoke pouring out of it! It can apparently work off of USB power, which is what I should have done, but since it came with the 9V adapter I thought "why not". Only AFTER the fact do I see that others have had the same problem.
After digging inside I see that the voltage regulator is literally fried. Instead of sending this thing back to China I went ahead and ordered a 10-cent replacement part.