"teach"
2. The inventor of the PalmPilot used a prototype made of cardboard for months, to see if it was usable. He would bring it to meetings and "use" it to take notes like it was the real thing! Here's a pic of one of those prototypes in the Computer Museum in Palo Alto
http://bambax.smugmug.com/Other/2012-10Californie/27080082_g...
If learning Keynote or a tool like Basalmiq is too much of a learning curve, I'm not sure someone should even be working in the world of app design? I know non-technical people that downloaded some Keynote templates and were slapping together ideas in less than an hour after reading some quick tutorials.
Also, as far as mobile prototyping goes, I'm a strong believer of higher-fidelity mockups since screen real estate is such a premium.
Pencil and paper doesn't have these problems except for the most anal-retentive of folks.
However I believe that digital linking and editing stages would be easier if it were on a browser than an iphone.
And the idea behind paper prototyping is to be able to discard without regret. Once you code, you can get attached to your first ideas and not iterate, or iterate over some arbitrary restriction set by the tools. Paper prototyping makes it easy to "kill your darlings" without regret.
More than that, the second and probably more important idea is to avoid the customer to get attached to an un-iterated design, and the "but it's almost done!" effect that can be devastating when negotiating times.
Just this past Thursday, we found a new task that our call center would have to perform. I opened Visual Studio, created a new WinForms app and layed out the UI within 20 minutes. I emailed the screenshots to all the principles and got responses back within the hour.