Last Updated: 17 May 2011
User Interface Design Tool (PowerPoint)
NOTE - 17 May 2011: Although this Powerpoint template is still good for basic UI design, I now generally recommend using OmniGraffle for wireframes. See Best of Breed Web Development Tools.
The SCTO User Interface Design Tool is designed to allow you to quickly create interface mockups of an application (web, desktop or otherwise) that you are building.
Its built on top of Microsoft PowerPoint to make it easy and accessible to everyone.