A number of tools designed for other purposes can be appropriated for Rapid Prototying. The benefit of these tools is that you might already know how to use them, thus your learning curve is short and you can get prototyping quickly.

• PowerPoint/Keynote: I always teach students how to prototype with presentation software. The ability to go to full-screen mode makes for immersive prototypes. Inject graphics, video, etc. and make use of the master slides for prototype templates. Attach mouse click and hover actions to any object to control the flow between screens (slides). Use ‘kiosk mode’ to prevent the slides from auto-advancing on every click. Really, you can make a pretty decent prototype in a very short amount of time, using a piece of software you already know how to use. Doesn’t support highly interactive elements, and there is no ‘below the fold’. Also, you probably already have this software, so it’s essentially free.
• Excel or Numbers spreadsheet software: You can use Excel to create some basic prototypes as well. Hide the gridlines, but make use of the grids to color in cells to block off different areas of your prototype. Use one sheet for each main screen of your prototype and create hyperlinks to control the flow between them. If you have to prototype something that involves ordering or calculation, you can actually make the equations work, because it is a spreadsheet. You can also embed graphics and other objects.
• Adobe Flash: I have always taught Flash to my Rapid Prototyping students. Over the years, I learned that this takes significant lab time: Flash is complicated. But the students get introduced to timeline-based prototyping, vector and bitmap based graphics (and how to mix the two), button state design, object-instance prototyping, and a comprehensive, well-tested GUI library. Obviously, they need to learn some basic Actionscript, and I have found from experience that sticking with Actionscript 2.0 makes things significantly more doable for my students, who typically don’t have strong programming backgrounds. The problems with using Flash are that the support for building accessible sites/apps is low, and Apple hardware is not supporting Flash, and Adobe itself seems to be giving up on Flash. Another issue is that graphical layout is fixed, rather than dynamic, so doesn’t tend to resize well. I will probably move away from teaching Flash in the next year or two.