"Many kids have their own computers. As parents, this poses a problem with computer safety; not only to keep your kids safe but to make sure they do not do something that will cause damage to OS. A great way to keep a leash on the activity is to setup the accounts as limited. Unfortunately this will keep some already installed apps from working, including some games. There is a solution to this problem. This quick and easy tweak will enable you to keep the account set as limited and still allow running of applications that require an Administrator account."
Check it out over at AOA Forums.