How can I reload original software back to nexus one I unlock my nexus one, and compile and install the ginger bread build load to the phone. But now, I realize that it does not have all the google software e.g. gmail, map, market, etc.

How can I reset my nexus one back to the original froyo with all the google software?

I have tried 'factory reset' but it does not revert back to android 2.2. Thank you for any idea.

Thank you.
Check out this thread, Original ROM, which is about returning a Nexus One to an unmodded ROM.