Squat Jacks

It's a squat.  It's a jumping jack.  It's a super-awesome exercise!  

Start in a standing position with arms straight over your head and feet together.  In one fluid motion, bring arms out to the side at shoulder height and jump your feet out into a squat while keeping your knees behind your toes.  Then, jump back into starting position.

It's quick, it's powerful!  Modifications are shown in the video to reduce the jumping.