Recently I built an image server. This allows me to add placeholder images to sites I build without having to go around hunting for clip-art, or downloading from somewhere.  The neat thing is that I have control over the dimensions of the images, and their content.  For example, I can go to http://images.dnawebdev.net/600/400 to see a random 600*400 image. Sites are user specified and up to a maximum of 1024*768. I can also add a subject in there, and see an image relating to that subject.  It's a bit like lipsum.com, but for images!

Here's an example of http://images.dnawebdev.net/300/600/marine

More details, and instructions on how to use it are up on http://images.dnawebdev.net