Recently when DS6 hit a teacher at school during one his anger outbursts he lost the Nintendo DS for 7 days. It was a wonderful detox for him. At first he was angry and talked constantly about when he could get it back but after the 3rd or 4th day it was almost forgotten. He played with things in his room that he hadn't touched in ages. When the 7 days were up we actually waiting for him to remind us to give it back to him. Took until almost mid-day.
We also have the rule about only keeping the DS in the car and he only gets to take the DS in the car if the trip is going to be longer than 20 minutes. For short trips we realized it wasn't worth the fight when we arrived at the destination.
Surprisingly DS6 is not as addicted to the Wii. I think it's because it is down in our basement family family room and he doesn't like to be alone. The DS is more portable and he can more easily sit near the rest of his family while he plays.
