http://edsome.com/2010/09/lesson-plan-geotweets/ Twitter network tweets out their location, and grouped students use Google Earth to find the tweeters location. Once they find the location, students Geotweet back. Lesson suggests using Edmodo or a blog to have students answer follow up questions.
Students tweet their locations and then use maps to find their locations to measure and convert their distance using math. Google Earth is used to find actual distance.