Sprint customers can now "use their existing Sprint mobile number as their Google Voice number and have it ring multiple other phones simultaneously, " according to Google.
This is actually great news technically and practically for Sprint customers. Now if only I knew someone using Sprint...
I'm not sure it's worth running out to get a Sprint phone, but the partnership does work both ways:
Alternatively, Google Voice users can choose to replace their Sprint number with their Google Voice number when placing calls or sending text messages from their Sprint handset. This feature works on all Sprint phones and gives Sprint users all the benefits of Google Voice without the need for an app.Google Voice is actually a great tool and this partnership looks like it works for both companies. Here's the video explanation from Google:
Here is the Google announcement
Official Google Blog: Sprint integrates Google Voice
and here is even more information on Google Voice
A Brief Explanation of Google Voice
Google Voice Extends Free Calling Through 2011
Port your existing mobile number to Google Voice