Ds6 has a DS at his father's house and begged for a while for one over here -- no way! I don't think he needs *more* access to video games!
Ds6 plays on the laptop here, though we have a Wii and an X-box too. He's much more into complicated RPGs with lots of statistics -- his usual go-tos are WOW and Spore. On his DS, he tells me he loves to play some Pokemon game with a loooong name (when he says it, it's like Ralphie in "A Christmas Story").
He has lots of dramatic pretend play involving levels, powers, spells, abilities, potions, etc., etc. He created his own imaginary game called Super[name], which has been evolving over the past year and half or so -- but remains surprisingly true to its roots, lol.
We don't have a time limit, but he usually plays for about half-hour on weekdays, and an hour or so on weekends. After I decide he's been on long enough, I simply tell him he's got 5 more minutes, and then that it's time to log off. He's learned that if he whines about stopping, then he won't get to play the rest of the day or the next day (and we follow through with that threat!).
We also use "No Video Games" not infrequently as a threat -- it makes for powerful bargaining. To use a Dr. Phil-ism, it's "his currency." It's amazing to see how quickly that threat works! The key to this is, of course, telling him you're going to do it -- and then really doing it, and following through the entire term of the punishment, one day or one week. And after a week, he's a little off it anyway and remembering more things to do on his own, and he actually plays less. So everyone wins!
Tracey -- of course he'll think it's mean for you to take away his gaming for a while. But he's 6 -- he can't regulate himself, so it's up to you! When we think ds needs time away, we simply tell him that we think he's been playing video games too much and that he needs to take a break. We explain that we've noticed that it effects what he chooses to do, and we think it would be good for him to do other things for a week.
We banned ds last year after he started getting in fights at school -- this was almost certainly because he was getting *no* stimulation at school, but we decided that video game fighting wasn't helping. So we banned it. He did fine with the adjustment. He even understood why we were doing it. He didn't play for a good 6 months. We let him start again, and he's eased back into playing -- actually, we're getting close to a "detox" period again.
I think as long as the child controls the video game, it's ok. It's when the video game starts controlling the child that you've got a problem.
Shari -- where is your ds taking a programming class? I'd love to have ds do something like that!