Last week I managed to get my GPS code to download the GPS "track" from my device and create an html file that uses the Google Maps API to display it as an overlay.
I spent some time trying to get the map to display correctly from within the normal blog pages but something was causing Internet Explorer to fail to display the tracks. Firefox and Opera were fine; I guess it's something to do with IE using VRML to display the track and the others using a server-side generated graphical overlay. Anyway, the file is here.