I really like PowerPoint because you can simulate interactivity, it's easy, and it's flexible. A few links: http://www.boxesandarrows.com/view/interactive http

I really like PowerPoint because you can simulate interactivity, it's easy, and it's flexible. A few links: http://www.boxesandarrows.com/view/interactive http://www.boxesandarrows.com/view/interactive http://www.krisjordan.com/2008/09/07/10-minute-mock-prototyping-tips-for-powerpoint/ http://www.krisjordan.com/2008/09/07/10-minute-mock-prototyp... http://www.istartedsomething.com/20071018/powerpoint-prototype-toolkit-01/ http://www.istartedsomething.com/20071018/powerpoint-prototy... There are tools specific to GUI-prototyping that have other upsides/downsides, a great list is here: http://c2.com/cgi/wiki?GuiPrototypingTools http://c2.com/cgi/wiki?GuiPrototypingTools