Google's Newest: Click to Call

I ran across a neat looking toy today on Google Maps. The service "Click to Call" works in tandem with the bussiness addressing and mapping features they already provide free of charge.

Basically, when you click "Call...", you enter your phone number. Google calls you, then automatically connects you to the company you've clicked call for. On both ends, Google's role is transparent, meaning:
a) Google's service only maintains your phone number for as long as is prudent to operate the service
b) When you get the call from Google, you see the companies phone number on your Caller ID
c) The company you call sees your phone number on the Caller ID

The service is accessible from any current Google Maps page.