Although dangerous, many people read and respond to e-mail while driving.  Smith Micro has made a wonderful product called Voice on the Go which allows users to listen to their e-mail messages and dictate responses to those e-mails without ever looking at their phones.  Smithmicro.com.

[podcast]http://evangelistmktg.com/audio/Technology%20Tailor_03-02-09.mp3[/podcast]