We have now updated the movie that allows you to test the screen on your iPod Touch or iPhone. It plays black, white, red, green, blue, allowing you to check for dead pixels. You can then check for the 'negative black' issue that so many are reporting, along with a gamma/contrast test and a gradient screen to check for banding.
The video can be downloaded here. Then drag it into iTunes or onto your device and touch play.
The new screens were supplied courtesy of http://www.lagom.nl/lcd-test/small/ - if you go to this website you can also download static versions of the images to load onto your device. There are also some additional test images on lagom.nl that we did not put onto the video, as the compression would have made them not suitable for testing.