Tire Pressure Monitor for Lazy Car Nerds

To check your car's air pressure, you could get an air pressure gauge, or kick the tires, but that wouldn't be quite as geeky as this aftermarket tire pressure monitor. Four caps with sensor read each tire's pressure and relay it wirelessly to the dashboard-mounted LCD. The setup also informs you if your tire rapidly deflates, alerting you of a flat. Coo, but two problems:

If the caps are indeed monitoring pressure, that means they depend on jamming a tire's internal valve open, meaning that your tires are going to need refilling often. Secondly, you are definitely going to lose these things. [Suzhou State Auto Electronics via Sci Fi]