Sometimes the pixels on an LCD can become stuck, displaying only some colors or appearing completely dead. These black or oddly colored spots are a pain in the neck but they're not always permanent. At some point last summer the Mac laptop I was working on got a stuck pixel and after scouring the internet for information on how to fix such things I came across instructions for fixing stuck pixels on the PSP that involved playing a particular video file, containing RGB pulses, and massaging the screen around the stuck pixel. The PSP technique worked fantastically and in a few moments my screen was free of stuck pixels. I have a similar problem on the machine I'm using right now but this machine has no means of playing .mp4 files (which the PSP pixel fixing video is) and rather than trying to figure out how to make it play .mp4 files, I thought I'd ImageMagick myself up a quick solution. To that end, I created three animated gifs that pulse at different frequencies (rgb3.gif, rgb5.gif and rgb7.gif), which serve the same purpose as the video and are substantially smaller in size (1.2KB vs 1.5MB). The great thing about these is they're essentially platform independant and require no video codecs at all. To fix your dead pixels, just fire up a graphical web browser, point yourself at one of the images, move the browser window so that the image is under your dead pixel, massage the screen a little and with luck the pixel may start working again. If you don't have any luck try one of the other frequencies and if that doesn't work, I'm sorry.
UPDATE: If you're here, you might be interested in Unsticking Stuck LCD Pixels: A Script