The cool stuff for school...

I recommend checking out Wired with their coverage of what's cool for school kids. They review computers to backpacks with some items that you might not have heard about. Like this one:

Tech Group WipeOut Chalk Dust Gun

There's a safer, lighter, much less messy version of paintball — only it doesn't use paint in any form. It's called WipeOut, and it comes as set of two guns, each of which holds and can shoot foam-tipped darts that leave a smear of chalk dust when they hit. The kit also comes with two pairs of safety glasses, because of course chalk dust in the eye would not be much fun. The guns are spring-loaded, so their range is considerably more limited than paintball guns, but as a parent I'm not sure that's a bad thing.
— Matt Blum