If you've been tempted to try the Gimp, the open-source alternative to Photoshop, but you've been put off by its non-standard interface, this is for you: GimpShop is a free program that does its best to make the Gimp behave like Photoshop. It's not perfect, and the Linux version is a little more well-behaved than the Windows or Mac versions. But it's definitely worth a try, especially if you're not ready to spring for Photoshop but still want a solid image-editing program.