Is there a way to use the Built In Mic on a MacBook or MacBook Pro for Mobile Phone Calls via Bluetooth? Is this possible? I thought I saw something similar on the Jaguar preview or unveiling? Is there a tutorial on the web you have seen?

I have done it using this program: BluePhoneElite 2

Essentially you are able to turn your Mac into a Blue tooth headset.

Beyond making calls I can then use a program such as Wire Tap to record voice mails or conversations should I need to do so.

Check your local laws for recording phone conversations. In Utah the law is that only one party has to give its consent. Of course that can be you, the other party does not have to be informed by law. You cannot however record a third party conversation unless one of the participating parties has given consent.