Photo Mosaics
Pet peeve: Dave Winer says that this is a "really great mosaic".
A photo mosaic is an image made up of a collection of smaller images. There are two ways to do them: The right way, and the easy way.
The right way is to find small images that represent the various pieces of the whole image without modificatoin. It's really hard to do since if you have, say, an eyeball, in the main image, then you need to find images that you can put together to form an eyeball. There is software that can automate this, and if you have a huge (huge) collection of source images, you can get good results. I've seen mosaics made up of frames from a movie that looked pretty good, because they had every frame in the movie available to use as a source image.
The easy way is to take any collection of images, shrink them down, and then just alter their brightness and hue to match whatever pixel you need at the location the image is going. That's what the image Dave linked to is doing.
Here's a mosaic that's done correctly, although without enough images, so the result isn't as good as it could be. This one actually looks pretty good.
