If you need to try out different color combinations, be sure to try Kuler from Adobe. This flash-based application lets you browse a wide variety of designer created color schemes as well as create your own. It supports all the major rules from Analogous to Shades. The controls are beautifully designed and the entire application really inspires creativity. In order to access it, you are supposed to have a live connection to the Internet. You'll need to be online to take advantage of the shared and highest rated features, but I've found a work-around for those times when an Internet connection isn't an option. I was able to save a web archive in Safari (File > Save As) which can then be opened up when I am not on the Net. Be sure to check this very cool application out.