Please refer to Making of the Google Nexus-One for 1st part

Part 3 – Testing
This video is dedicated to testing environment of HTC and Google. Video included many test like tumble test, button test, drop test etc..

Part 4 – Manufacturing

Related posts:

1. Making of the Google Nexus One
2. Nexus One vs iPhone
3. Google Latitude for iPhone (Mobile devices)
4. Google Sync for mobile phones
5. Google voice search coming to iPhone