Many new ways to monitor the game play of kids are being introduced. For example, Nintendo just announced that all Revolutions will come with a parental control (see story).
Woog Laboratories has announced that they have created a PC Moderator to "tackle the problem of computer addiction, particularly among teens."
The PC Moderator is hardware that attaches to the PC’s video port (VGA or DVI). Parents may then configure the device with passwords and time limits for up to eight users. When time runs out, the PC Moderator will block the video signal from the PC to the monitor.
And yes, the creators did think about how you may want to impose violence on the device to prevent it from stopping the game. It is equipped with an eighteen-gauge, stainless steel case and is padlocked.
Come on, kids, you know you want to add this to your Christmas list!