http://www.engadget.com/2012/05/25/leap-motion-gesture-control-technology-hands-on/
http://leapmotion.com/

I think they might be onto something, but of course it's difficult to judge just by their site and the movie.

What do you think? Would you game with it, use it for other purposes? Or is it just another useless gadget? Would you pay 70 dollar for it?

I just might.

Looks preferable to a touchscreen or trackpad. Wouldn't replace my mouse, though.

For $70? I just might, just to try it out. Would most likely be higher though, given VAT, S&H, and any other possible increases in the price I'd have to pay as a European.