What would you use a pressure-sensitive keyboard for?

This prototype keyboard from Microsoft might change keyboards as we know them. Or it might go over like a Segway running Vista. It all depends on the answer to this question: Is a pressure-sensitive keyboard useful?

The video above demonstrates the potential of the technology, showing practical uses like pushing harder on a key in a game to make a character run faster. It can also use the amount of force to determine whether you want to write in lower case or all-caps. My favorite: How hard you hit the Delete key determines whether you want to delete a character or a word. Presumably slamming it as hard as you can will wipe your entire drive.

Whether or not that sounds sexy to you, the idea is much closer to reality than most concepts for a few reasons: 1) A working prototype exists. 2) This is Microsoft. 3) The keyboard uses existing tech, with rubber domes underneath every key pushing three flexible membranes. Because of the design, the harder you push, the greater the area of electrical contact, which can be easily measured.

Want one of these? What would you use it for? Let us — and Microsoft — know in the comments, and look below for pictures of the prototype.

UIST 2009 Student Innovation Contest, via YouTube