I saw two things in the past week that made me think about Keynote as a prototyping tool for interaction design. First was Steve Mulder of Molecular showing a PowerPoint prototype at the UXWeek panel, ‘Next Generation of Web Applications’. Second was stumbling over the Flash export panel in Keynote.

With about 10 minutes of design and another 5 minutes of debugging, I was able to slap together this prototype using Keynote and save it out as a Flash file. Using the prototype you can (a) show/hide a panel, (b) add an item, and (c) delete the item.

Obviously, Keynote as a prototyping tool does have some limitations, but it also seems an appropriate light-weight choice when you want to evaluate or communicate a linear progression of interaction.

Pros:

• It’s really fast—admittedly, this isn’t a great prototype, but it took <10 minutes.
• It’s very portable—it’s useful for communicating with clients or testing with users.

Cons:

• You can’t convey hover—there’s no way to create passive highlighting, pop-ups, or change pointer icons.
• Linear logic only—although the path of the interaction can branch, Keynote really can’t support much logic beyond what a Choose-Your-Own-Adventure book can support.

Oh, and here’s the Keynote file I used to create the prototype.