Online Summer Camps for Tweens?

This Common Sense Media link came through my inbox and caught my attention - for obvious reasons. Online summer camp? It sounded ridiculous to me, but I clicked through and...
It's not "summer camp", not in the way you're thinking, but some IS interesting and maybe useful for that work call or 100 degree day. Some are free, some not. Here's the link and below are Common Sense Media's top picks. Take a look for yourself!*
Oh - and I have my crack team of 'kid testers' (the Lee children, ages 6-12), trying each out. They've promised to review sites, so check back soon!
Common Sense Media - Online Camps
start with a book
camp with google
DIY
make
khan academy
brain chase
wonderopolis
connected camps
techrocket
* let's build does not endorse or promote any site. just providing info - be sure to check them out for yourself!