The things I took away from reading Niven was transfer booths. The world has homogenized because information and people were transmitted instantly one from corner of the globe to another.
Ooohhh boy.
If you want to see this idea taken to the next level, you should read Dan Simmons' Hyperion Cantos. ;)
I loved the conservation of momentum "hack" for those teleportation booths. Go on, everyone who hasn't read it, see if you can guess how he dealt with that.