There are many existing MBL activities written for the Earth science explorations. Vernier Software , a national leader in the development of reasonably priced MBL software, sensors, and interfaces, publishes "Earth Science with Computers" which includes over 40 Earth science experiments. They also publish "Earth Science with Calculators". Pasco Scientific also publishes several experiments related to the geosciences with associated software, sensors, and interfaces available at reasonable prices.
Care should be taken to provide students with an interactive "hands-on" and "heads-on" learning experience when selecting MBL activities for you class or when designing activities of your own. MBLs are ideally suited for interactive engagement or inquiry based activities because they are easy to use and can help make learning spontaneous and fun.