The Breathometer™ is "The World’s First Smartphone Breathalyzer!" It's small enough to fit in your pocket and on a keychain. If this would have been available when I was younger, it would have saved me several tickets. Then again, I was young.
All you do is exhale into the device after you're out with your friends, and it will give you the blood alcohol level on your phone. Hand the keys over to a designated drive or call a cab. Watch the video - it's great.
And for those who don't know what pledging is - you're supporting an entrepreneur trying to make it big with a product. Or you simply believe in their campaign and wish to contribute to them. Prices vary, and the more money they raise, the more they're able to produce and promote a particular product. This one starts with $20 and you'll have your product by the summer.