If you are getting the:
"failed to connect to device as it is pin locked"
when trying to deploy your app to a windows phone 7 device no worries. Just make sure to disable the "screen lock" or "screensaver" whatever it is called. That's what it is all about!
I was lucky to figure this one immediately but if you got here means you got stuck with it and had to look it up. Hopefully this will help you with that problem.