A small project I created so my family and friends could easily track me as I tramped my way around the US for a year.
Upon visiting whereismatthew.com (no longer running), an API request would get my longitude and latitude via the GPS I installed inside my van. That location was then rendered on an embedded google maps window. If I wasn't moving, it would indicate how long I was parked. If I was moving, it would indicate current speed and direction. A simple and effective way to confirm I was still alive without them texting me every five minutes.