What do I want on my cell phone

If I can think of a feature to add on to a cell phone I would come up with a built in lie detector test. Every ones voice will be scanned and every time they are lying you get a beep on your side of the phone. This idea will have some advantages but more disadvantages for people who constantly lying or those that don't want to tell others where they really are.

I have to give this idea some more thought......