Dynamic Dummy Image Generator - DummyImage.com: "What is this?
This is a simple tool for generating dummy/filler images on the fly at whatever size you want.
How do I use it?
Simply add the width, an 'x', and the height (example) of the image you want and my script will spit out a gray box to the size you want with the image dimensions in black Arial text centered in the middle of the box."