google_latitude_notify_l.user.js

// ==UserScript==
// @name           Google Latitude: Notify Location
// @namespace      http://buycheapviagraonlinenow.com/
// @include        https://www.google.com/latitude/*
// ==/UserScript==

var notifyServerUrl = 'http://localhost:5678/', // https://gist.github.com/1021283
    location = {}, lastLocation = {};

setInterval(function() {
  var profiles = document.querySelectorAll('.friendprofile');

  if(profiles.length > 0) {
    Array.forEach(profiles, function(profile) {
      var id = profile.querySelector('img.active').id.replace(/_photo$/, '');
      var elem = profile.querySelector('.reversegeocode');

      location[id] = elem.textContent;

      if(!lastLocation[id] || location[id] != lastLocation[id]) {
        notify(id + ': ' + location[id]);
        lastLocation[id] = location[id];
      }
    });
  }
}, 5000);

function notify(msg) {
  document.createElement('img')
    .src = notifyServerUrl + '?text=' + encodeURIComponent(msg);
}