I thought I would follow up the last post with a simple way to check your LCD monitor for hot and/or dead pixels. This process is especially handy when you purchase a brand spankin' new unit.
The first step is to create a completely white picture and a completely black picture. The next step is just to view & fill your screen with white.jpg & black.jpg respectively. Using white.jpg look for anything that's dark (a dead pixel). Using black.jpg look for anything not black, usually blue, green or red (hot pixels).
Check the max resolution of your monitor and create an image in Photoshop that large or slightly larger. 1600x1200 should be fine for most people. Next take the paint bucket and paint the image white. Save your image as white.jpg. Next select black as your paint color and using the bucket make the entire image black. Save this as black.jpg.
Hmm, just realized I'm not sure how to do the next step for a Mac system. Well you need to completely fill the screen with your image. Maybe some nice Mac person can post how to do that.
For Windows users, open your white.jpg in the Windows Picture & Fax viewer (right click and hit preview or open with...). Hit F11 to start the slideshow and hit pause in the upper right corner. Move your mouse off screen and in a few seconds the control panel will disappear leaving you with (hopefully) an entirely white screen. Spend some time staring at the screen (I usually check it as quadrants for ease). Spotting individual pixels is not easy so don't rush. Next switch to black.jpg and look again. This time look for pixels that aren't black.
And that's pretty much it. A couple of minutes and you learn quite a bit about the condition of your LCD monitor. If you find 8 dead pixels you LCD is considered defective per most manufacturer's policies. However I always try to get a product with zero.