We all know that it's not a good idea to make phone calls while driving; indeed, in many jurisdictions it's flat out illegal. The problem is, though, that it's just too easy, and maybe too tempting, to just reach out and touch someone while in the car. If you need a little help remembering, there's the Phone Condom.
This zip-up plastic bag comes pre-printed with messages like "Park Your Phone: Drive Your Car" to remind you of the potential for problems if you drive and talk. Created by Innocorp, Ltd, a Wisconsin company focusing on safety and prevention concerns, this is a low tech solution to a high tech problem. Sure, there's nothing to force you to stick your phone in the bag, but frankly anything that makes you less likely to make that call when you shouldn't is a good thing.
You can order a Phone Condom from their website for $1.99. While it's not free, if it helps keep you safer, it might be money well spent.