The guys over at ConversationsWithMyself.com have created a method to use a real-time, web-based GPS tracker using the Google Maps API. (Warning: This how-to is a bit technical) This page helps you to create the tracker using the following software:
1. Python (xmlrpclib, pySerial, pyGPS, Zope)
2. GpsGate (gps simulator, 14 day trial)
4. Get a Google Maps API key.
The site gives you all the code and instruction required. Have fun!