xPocket is a Web app to control an X-10 Model CP290 Computer Interface from an iPod Touch, iPhone or iPad. Install xPocket on a Mac with an attached CP290. Nothing is installed on your iDevice and it doesn't need to be jail-broken. You will have to edit an HTML file, but HTML skills are not necessary.
Note: Although Finder indicates no version number for this application, the developer refers to it as version 2.0.