This code snippet will allow you to generate thumbnails of images by visiting a URL such as yoursite.com/thumbs/images/myimage.100x100.jpg. This will create a 100px * 100px thumbnail of yoursite.com/images/myimage.jpg. The image will be stored on your server in yoursite.com/thumbs/images/myimage.100x100.jpg so the next request for the same image will be loaded without loading php. This will give you a very fast image caching system.

I was building a site for a client and all imagecache stopped working before I uploaded to the live server.

When I uploaded, all of a sudden imagecache stopped working. I checked the usual things (permissions, original image exists) and everything was fine.