Measure areas using Google Maps!
The page remembers your most recent position/zoom/map-type for the
next time you visit.
If you haven't visited before, it tries to figure out your location
based on your internet address.
The area computation is done using spherical geometry, so it's
correct for large regions.
The lines between points are drawn as great circles, to go along
with the spherical area math.
Lines that cross the International Dateline do work, with
a small gap in the line.
(Google Maps applications tend to have problems with the Dateline.)
Areas that span more than half the globe may display strangely.
Map courtesy of the Google Maps API.
Other Google Maps apps: Paris Star Forts, Transpac 2005 Tracks, BART Map/Schedule, Paris Metro Map, USA Hot Springs.