Design Commission has made a cool stencil kit that makes it easier to sketch nice looking interaction designs by hand. The kit includes a metal stencil, a mechanical pencil, and a sketchpad with browser chrome and grid.

If you browse around YouTube, you can find a good deal of videos showing how people have used lo-fi prototypes in different projects. Here are four interesting ones that I've found.

It seems like Adobe is really keen on winning the hearts of interaction designers. At Adobe TV, they have published a series of tutorials showing how to use Fireworks for creating rapid interactive wireframe prototypes.

In this video, Johnny Chung Lee, the guy behind the do-it-yourself interactive Wii based whiteboard, shows how he prototyped a drinking glass that, when placed on the Microsoft Surface table, can alert a waiter to offer a refill.

Alexa from adaptive path has made her own magnetic prototyping kit for mocking up an Aurora-like mobile device interface. She picked up a pack of Inkjet Magnet Sheets and printed her very own custom-made magnetic interface widgets - "no ActionScript needed!"