It's good for games.

I can also see a use for keyboard shortcuts: Press lightly to delete a letter, a little harder a word, harder still a line, and really hard for a paragraph.

4 levels of modulation might be too much for accurate use, but three should be workable.

Maybe it could be used to reduce typos--when I mistakenly hit "K" on my way to "P", I bet I do it with less force (at least most of the time).

It's not a computer keyboard, but there is a good use for this that's been around for years - midi piano keyboards.

I would save up system notifications, so when you're really in the swing of typing and REALLY FURIOUS, your system would freeze momentarily and a cheerful avatar would popup and ask you about updating your antivirus program or tell you you have unused icons on your desktop.

hehehe.