Definition# 10
from "Google launches apps for sharing Latitude location"

1. Google Latitude
is a location-aware mobile app developed by Google. Latitude allows a mobile phone user to allow certain other people on his or her Gmail contact list to track where he or she is. These people can track the user (or more accurately, his or her phone) on Google Maps via their own iGoogle accounts.

2.Google Talk
(GTalk) is a free Windows and web-based application for instant messaging and voice over internet protocol (VOIP), offered by Google Inc.
Instant messaging between the Google Talk servers and its clients uses an open protocol, XMPP, allowing users of other XMPP clients to communicate with Google Talk users. VoIP in Google Talk is based around the Jingle protocol. The technology used within the Google server network however is not publicly known.

3.Fire Eagle
is a place for you to store information about your location. Once your location is in Fire Eagle you can then choose to use it in all kinds of places all over the web.
Nothing is shared without your permission, you can choose how much information to share and you can change your mind at any time! Fire Eagle gives you control over your location.

4.Google Talk Location Status (beta)
Share your Google Latitude location as your status message with all of your Google Talk or Gmail chat contacts, including anyone that can already chat with you.
Automatically updates your status message with your current city's name as you move.

5.XMPP
Extensible Messaging and Presence Protocol (XMPP) is an open, XML-based protocol originally aimed at near-real-time, extensible instant messaging (IM) and presence information (e.g., buddy lists), but now expanded into the broader realm of message oriented middleware. It remains the core protocol of the Jabber Instant Messaging and Presence technology. Built to be extensible, the protocol has been extended with features such as Voice over Internet Protocol and file transfer signaling.