Cool! I have also heard of a few other related things:

http://www.fongo.com/ (And I thought there was another one out of the Waterloo area but can't find it, maybe it was this. )

http://www.freedompop.com/

https://angel.co/signal-mobile

Ya, exactly. When I meet someone. Why not be able to just start typing their name and add them that way. If they change their number it can be updated automatically so I have the new one.