That task isn't really all that hard:
You'll need a small application on your mobile phone that:
- Uses the phone inbuilt/external GPS device to discover the phones longitudinal and latitudinal coordinates (elevation is usually also included).
- Send the information discovered in step one to your server along with a UTC timestamp and the phone's ID (a simple WebHttpRequest will probably do). You should also include an option to let the user choose either the time interval between two GPS measurements or a certain travelled distance threshold.
You'll also need an application on your server that:
- Receives timestamp, long/lat coordinates plus elevation and the phone ID and stores these in a SQL database.
- Query the database for coordinates of a certain phone ID within a certain timespan
- Generate HTML page utilizing Google Maps JavaScript API v3[^] to plot the points onto the map.
When returning the coordinate data (JSON format maybe) you should take the zoom level of the map into account to make sure not to return to many points that way to close to each other to be discernible.
Regards,
— Manfred