If you want to build a device to talk, dial, and hang up hands free while driving. My book on to build such a device is on promotion free at the Amazon Kindle store this week.
http://www.amazon.com/Electronics-Project-Znidarsic-Science-ebook/dp/B007OWFI3G/ref=sr_1_3?s=books&ie=UTF8&qid=1356457228&sr=1-3&keywords=frank+znidarsic+science+books If you don't have a Kindle you can download the software for it from Amazon free on your computer. Merry Christmas and please drive safely over the holidays. Frank Znidarsic
