I think you've made the right choice to not let him go camping - follow through is very important with rule setting (so I'm told) BUT I think banning the Xbox, DS etc as WELL as not going camping is a little too much. When you discussed the action and consequence type rule system with him, you said there would be one punishment if he gathered three strikes. If you don't let him go camping AND you take away his computer stuff, that's two punishments for the one crime, iykwim?

Otherwise, good on you and good luck with your study today!
i feel bad forcing that rule aswell, but we limited xbox to weekend use only. so i can go back on that rule because he has been rude and is being punished and made to stay home.

we did this so it encouraged him to use his imagination with his toys or go outside and run around etc. otherwise during teh hollidays we found he would just sit and play computers all day. so it isnt a "punishment" as such, and i prob should of explained that better before its a house rule,