My students made a solar system model in Second Life. It was an interesting class because the 4th, 5th and 6th graders learned at the same time. I assigned three different notecards in three different levels and I sent them to three different sandboxes. My grade 4 students made a static model of a solar system. They resized the planets to visualize the relative sizes of the planets and they sequenced them. THe 5th graders did a more difficult challange. They added clickable information in each planet and make the planets revolve around the sun. The 6th graders improvised the solar system by rotating the planets as well as revolving them.
My youngest students were learning about rocks last week. One of the first thing they learned in this unit was igneous rocks. So...it was time to take off to the volcano in SL and bathe in magma. The volcano was almost realistic. It had burning magma, gas and it erupted every hour. (My students screamed when the eruption started) However, there we no notecards we could learn from at all. So while my students were busy jumping into the magma I was busy lecturing them in the local chat. :(