This reminded me of a little suggestion by Bret Victor (http://worrydream.com/MagicInk/#reducing_interaction).
Imagine honing in on familiar areas simply by typing the first few digits of a zip code—type “9” to immediately zoom into the US west coast, followed by “4” to zoom into the SF bay area and then “5” for the east bay. Because of the immediate feedback, the user can stop typing when she gets close enough, and use relative navigation from there.
I coded up an example a little while ago (http://andrewcou.ch/zip-to-it/).