Contraption Maker – Solve problems, puzzles, brain teasers while creating wacky machines. Hands-on problem-solving leads to great fun and independent learning with the right curricular wrap-around to make connections between what kids are doing and what they need to know.
"On its own, Contraption Maker is a wonderfully entertaining game. At this point, the game lacks any structured curriculum or lesson tools (although they're promised in the near future). So, for now, teachers will find that any subject that requires problem-solving, understanding of cause-and-effect, and systems thinking can use this game to bring those points home. Whether bringing up examples in class and having students talk through possible solutions, or having kids play as a means to opening conversations about more serious types of systems and problems, Contraption Maker is a great way to get kids talking and thinking, and to cement learning through experience." (Source)
Virtual worlds can inspire students to try things out in the real world. Watch Audri's Rube Goldberg Invention. It's pretty impressive! See also Algodoo.