Wapdroid is a utility that monitors it’s location and turns wifi on or off based on it’s proximity to known networks and also monitors and updates the ranges of known networks with the intent to extend battery life.

Changes:

v2.1.1: rebuilt to include 2.0 support v2.1.0: increased responsiveness, lower memory & power usage, added notification options

http://code.google.com/p/wapdroid/