If you are the type of person that always hang out with friends, drinks a lot and drive, Breathometer is one of the best handy gadgets you might want to get. It is the smallest smartphone accurate breathalyzer that is capable of measuring blood alcohol concentration (BAC). The user just need to connect to handsets via the audio jack and blow into the gadget and it will register the blood alcohol level with its corresponding application. Having a small size you can easily keep it on your pocket or hooked up to a key chain.
For those of you out there who have some sense of self-discipline, you might really want to have this gadget which will tell you whether you have had too much to drink, where you can then make a more informed decision of hitching a ride back with a friend or to take a cab. The Breathometer sells $49.99 a pop, which is compatible with iOS and Android devices only. If you want to check their certification and documentation, do bear in mind that the Breathometer has already been officially registered with the FDA for that added peace of mind.