They were originally designed to simply make phone calls without tying callers to one location. But today's cell phones can do so much more, from snapping digital photos to sending text messages to playing video.
You can add one more feature to the list: a sobriety test.
That's right, cell phones with built-in Breathalyzers are set to hit the U.S. market. So after a night of too much to drink, you can pull out the device to see if you're fit to get behind the wheel.
South Korean manufacturer LG will introduce the LP4100 this year. The company placed several models on the market in that country last year and already has sold more than 200,000 units.
The phones were previewed at the annual Consumer Electronics Show - CES - in Las Vegas earlier this year.
Here's how it works: Users blow into a small spot on the phone, and if they've had too much to drink the phone issues a warning and shows a weaving car hitting traffic cones.
"So they test it and it says don't drive so they leave their car or call the taxi," explained Sung Mee Cho of Seju Engineering Inc.
The company also sells plug-in Breathalyzer adapters for some phones. None of the models tell you exactly how much you may be over or under the legal limit, but it can keep you from making other alcohol-related mistakes.
The LP4100 also allows users to set up the phone so on certain nights and after a certain time they do not call certain people in their phone book. Think ex-boyfriend or ex-girlfriend.
If you have a blood alcohol level over .08, the phone will not let you dial that person. So it not only promotes sobriety, but chastity - and probably your dignity, as well.