From finding a place to eat in a new city to navigating a detour to geocaching, GPS is an amazing technology. But just how does GPS work? NASA's eClips channel on YouTube has a good student-friendly explanation of how GPS works.
Applications for Education
Geocaching is a fun activity for students to do to learn about latitude and longitude, to discover geological features, learn or relearn basic math concepts, and to practice good digital citizenship. Seven years ago Jen Lefebvre, née Deyenberg wrote a great overview of geocaching in an education context. You can read that blog post here. When Jen wrote that post you had to use handheld GPS units to go on geocaching activities. Today, you can simply use the Geocaching Android app or iOS apps.