Meet SmartMat: a smart floor mat that connects to your WiFi network and detects the weight of people or pets to trigger actions of your choosing. Think about the possibilities here. You can use something like this to track who is coming to your home, how long your pet has been sitting outside, or even turn the lights on automatically when you enter.
SmartMat is a thin floor mat with smart plastic film that is force sensitive. It lets you use different combinations of triggers and actions to get things done. You can use it to send alerts, control WiFi connected devices, update Twitter, or control your smart phone products. It does have a battery but you can connect it to an AC adapter to run it all day long. The SmartMat can be controlled from any computer or mobile device. The project is on Kickstarter right now.