Here’s a neat application that I stumbled upon this afternoon. Custom Maps for Android allows you to use .jpeg and .png images of any map to create a custom GPS map. To use the app add an image to your phone then specify two or more latitude and longitude points that are common to your map image and to Google Maps. The Custom Maps application will then allow you to find the distance between where you are and a point on your custom map. You can also use the your custom map without a GPS signal, but it does lose some functionality. You can find the tutorials for using Custom Maps for Android here.
Applications for Education
We have some walking trails connecting the middle school and high school in my district. These trails are used for cross country running, skiing, and snow shoeing during physical education classes. Because the trails are so wooded, they don’t appear on Google Maps. It might be a neat project for the students in my district or districts like mine to create custom maps that could be used by other students, teachers, and community members utilizing the walking trails in town.