Small world and/or great minds think alike. I just came across this myself trying to make calls thru automated systems.
Wouldn't it be killer if I could use my imac as a handsfree - as this is where I'm working with the phone.
Audio input is via the built in mic, and output is via speakers or external speakers (as in my case)
Even have a small window that replicates the iphone interface dial pad - so I could even navigate in-call menus, such as "press 1 for directory" - it'd make life a lot more productive.