Okay, I have started setting up a dedicated page for the marathon realtime tracking. Still testing the set up but so far it is looking fine. The current plan is to display the tracked points and my current speed in a table and to put a dot on a map of Berlin to show where I am. This is done by instructing the phone to send out coordinates every minute, receive them via SMS on the server and pass them to a script that does the nice voodoo.
Unfortunately, the web world uses different formats for GPS coordinates (berliner-stadtplan.com uses degrees and minutes in decimal notation, the Benefon Track Pro phone spits our degree/minutes/seconds only and for realtime mapping you want degrees in decimal notation only) but I found a handy online converter so that helped to clear the confusion.