mock_geolocation.user.js

// ==UserScript==
// @name          Mock Geolocation
// @description   MONKEYS!
// @version       2009-01-19
// @namespace     http://andrewdupont.net/greasemonkey
// @include       *
// ==/UserScript==

// Mock geolocation. Ugh.
if (!('geolocation' in navigator)) {
  navigator.geolocation = {
    watchPosition: function(success, failure, options) {
      var position = {
        coords: {
          latitude: 30.2696384,
          longitude: -97.74947,
        },
        accuracy: 10000
      };
      success(position);
      window.setInterval(function() {
        success(position);
      }, 10000);
    }
  };
}