Free 411 calls

I have to admit I'm guilty of calling 411 a lot more than I'd like.  You're driving around and you need directions to a store or you want to call a restaurant and what do you do, you call 411 for the number.  Then you get your cell phone bill and realize you paid a dollar a call!  Well now there's a free 411 service if you are willing to listen to a 20 second ad.  I found this on Real Simple:

800-FREE-411

Another solution is to keep a phone book in your car.