Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A great way to practice spelling and reading

I bought these for my son, who is seven, and they are pretty fun, but he is a tad too young for them. I'd say they are for kids 9+. They are very cool, however, and the head mounted display really works. They are also imminently hackable as a simple wearable pda/communicator. It'd be cool to find other uses for these. Anyway, I had to put ours up for auction.