[Entrepreneurship] Ideas already done..

Laptop triple screen
So a few years ago, I had this idea of extending the laptop screen by having a flip out monitor or a panel that extends out. However, after telling some friends and they did some research, it was already done. One innovative idea dashed. Here are a few existing ones.

Shoe accelerometer
So, a few days ago I thought, why not put an accelerometer into a shoe and it'll know how long you ran for, how fast you went and how far you ran. The data would be very interesting to analyze such as when you started slowing down, when your form changed, etc. However, of course Nike would've already had something like this.
It's pretty cool, check it out: http://www.apple.com/ipod/nike/