I think Ribbit has the right idea. The best way to find out what works is to stop guessing and just try it.

From VentureBeat (yesterday):
“In a nutshell, Ribbit for Salesforce transforms phone calls into another data object that users can interact with. It automatically logs all calls and voice messages; users can then see all of their voice correspondence with a specific customer, or all correspondence related to a specific campaign. Ribbit can also transcribe your calls and messages, making them searchable and easily readable when you’re in a meeting or tight for time.”

(link)

Om, back in December was less than enthusiastic, but I’d love to see an updated review.

(link)

The main question is, when will Google attempt this? Indexing and organising all the Milky Way’s information has to include voice tracking further down the line…maybe taking Skype off eBay’s hands wouldn’t be such a bad idea?