USB automatic start sensor

[hupp3l]

Hi, this is my first post and I hope someone can guide me a bit. I basically want to build a small USB sensor, that when it senses movement, it will send a signal, and it will automatically open my browser for instance.

I actually do not care what interface it uses, but I figured USB would work.
Thank you for any replies.
O yes and I want to do it as cheap as possible.

 

[casper]

you can use an atmel avr with software usb interface.
This web site have a lot of projects:
**broken link removed**

 

[hupp3l]

Wow that looks really complicated. I read in another forum about possibly using a parallel port which would be a little easier.

Which is a sensor you would recommend?