According to an article on the website of New Scientist, Google [GOOG] has more telephony tricks up its sleeve besides its Android phone OS. In fact, a patent filed in 2007 was published this week that shows Google investigating "instant bid" technology for wireless connections.
How's it work? When your phone wants to initiate a call, it broadcasts a request for a connection from its radio. All available networks automatically return a list of price offers for the service of making your call. Presumably, networks with more traffic would bid higher, and networks needing traffic would bid lower, and your smarty-pants phone would choose the lowest bidder. This would all take place outside the realm of phone contracts or monthly service plans, of course; it's pay-per-call.