John Coryat is back with 2 new US-based boundary mapping tools!
Encoded Zip Code Polygons:
Plot the boundary area of any US zip code on to the map as a polygon. John shares the following: ..This one is especially cool in that it uses a Douglas-Peucker algorithm to compute the levels part of the encoding scheme that we wrote in Perl:
http://www.usnaviguide.com/google-encode.htm (open source Perl module)
http://www.usnaviguide.com/douglas-peucker.htm (open source Perl module)
NPA Boundary Map (telephone area codes):
John describes this map tool: "..This one is very useful to anyone looking to see how an area code is layed out in the real world. The data should be fairly accurate. Either click on the map or key in an area code. It can also be accessed directly by including a parameter: http://www.usnaviguide.com/areacode.htm?n=607 (replace "607" with your area code)
See the rest of John's great (and very useful) Google Maps tools here..