Edte.ch: Maths Maps

Maths Maps is a collaborative project where participants use Google maps to choose a location within one of the cities highlighted, then create a Math problem about the site. The problems are marked on the map with various colors depending on the grade level. Participants then send a Twitter message to announce the new problem. While the posted problems seem to be created by teachers, it would make an excellent activity for students to create some of their own.