Everyone has great suggestions. I like Jayne's especially. I thought I was in this boat last year when DS was a freshman, but he seems to have pulled it together.
I do think kids want limits set for them. They'll keep pushing, but they want the limits--I guess it reinforces that someone cares. I keep telling my kids that sleepovers have nothing to do with sleep, waste the next day and all the fun can be had during the day. I'm hoping that when they go away to college, they might think about that and not stay up all night.
My kids are younger but enjoy gaming and I try to limit it. Still, it's more than I'd like. One DS like My SPace and you tube alot. So much time spent on those. For the high school kid, DH & I were out of our minds last year--it would be SO simple to get As. Just do the work...a lot of it busy work, but we all have "chores" we just have to do (scrub floors, laundry..) We kept saying that he could have lots of freedoms if he just did his work. I'm crossing my fingers, but he's fine so far this year. One thing is that he's on the soccer team and practices 3 hrs every day. It doesn't leave a lot of other time so he's had to become pretty disciplined about homework. Maybe your son needs to have another activity that will take a big chunk of time so he can focus. Like Jayne said, we become depressed when we lie around.
Finally, I am convinced that the talent search (or even pre-college) summer institutes are important motivators. They're surrounded by other very bright students for 3wks (without gaming) who are driven--it gets them excited about doing well.
