Ah, this is cute… at least for those of us who are Mac users and have an Asterisk server managing our phone systems…
AsteriskC2D is a utility that allows you to dial a number directly from Address Book. After you’ve configured it in System Preferences you can click on a number in Address Book and choose ‘Voip Dial’. Your Asterisk server will call you and, when you pick up the phone, will call the selected number.
There are also plugins for QuickSilver and OnMyCommand which allow you to highlight a number almost anywhere in any application, and dial it on a real phone system quickly and easily.
You do need some configuration on the Asterisk server which, like most Asterisk configuration, is not for the faint-hearted, but it’s worth it.