Hi msjay,

The good news is, you and your son are NOT alone on this one! Lots and lots of 5 year old boys are diagnosed with a big case of the wiggles in kindergarten.

The first thing I would think about is making sure that there's enough time built into your son's day for him to expend energy in a productive way. Most kindergarten classes have 2-3 recess periods. Even if it's not a full-on trip to the playground, most students (especially boys) really benefit from just a few minutes a few times a day of body movement. Check with your teacher to make sure this is the case in your son's class.

Secondly, I'd try to work with the teacher to focus more on positive reinforcement than on punishments. If she could "catch" him and compliment him every time he DOES sit still for a few minutes, he'd probably learn pretty quickly how good it feels to have the teacher happy with you ("I like the way you're sitting in your seat and doing your work!"). You could also get a bit more structured and set up a star chart where your son earns a star ever time he completes an assignment on time or sits in his seat for 10 minutes without popping up (and a reward after earning so many stars).

Finally, this is kind of "out there" but my son's first grade teacher recommends that the "wiggly" kids in class bring a "fit disk" to school. It's actually a piece of exercise equipment and it fits in their regular school chair. They have to kind of balance to stay on it and the teacher says it's like "glue" for kids who used to pop up and down. I'll post a link to it on Amazon below...costs about $20.

Good luck!

Both answers were great!  Kat had a great idea about the fit disk.  I teach special education and I have found that these work great.  It gives just enough movement to keep them in their seat.  I have seen some classrooms even use exercise balls.  Good Luck!