Sustainable Softworks has released Phone Amego 1.1.13 ( http://www.sustworks.com/site/prod_phoneAmego_help/PhoneAmegoHelp.html), an update of the Mac OS X (10.5 and later) tool designed to make using your phone easier when you’re near your computer by providing on-screen caller ID, letting you click to dial a phone number from your Address Book or on your screen, and optionally dialing through Google Voice.

Version 1.1.13 offers several user interface improvements including minimizing an active call window to the Dock, an option to translate mnemonics (letters in phone numbers), and remotely dialing a landline phone attached to another computer running Phone Amego sharing. Phone Amego is Universal Binary so runs natively on both PowerPC and Intel Macs.
In addition to Mac OS X 10.5 or later it requires: a Google Voice account or a compatible Bluetooth cell phone or a landline phone connected through a compatible USB modem and caller ID service or VoIP phone connected through a Linksys/Sipura VoIP telephone adaptor.

It costs US$20, though version 1.1.13 is a free update for registered users. A demo is available for download.