Instructors looking to add a class mapping assignments that include a 'field work' component should take a look at EveryTrail. EveryTrail is a free service that allows you to record, visualize and share any trip using geotagged photos. New to the site is a free iPhone app that let's you track your hikes, walking tours, or field work using the iPhone as your geotracking device.

You can read more about EveryTrail here: http://www.everytrail.com/