For the time being I’ve created a ’start page’ to guide the kids towards a collection of known to be acceptable web game sites and such, that’s already a lot better than having them go through Google Search (because the youngest at least hasn’t heard of bookmarks yet, or even typing something into the location field). If that doesn’t help enough, I’ll consider the aforementioned list of allowed sites.

Not as a parent, but as a teacher, yes, I have experienced something similar. In my computer lab, we used to have a lot of problems with this. The hard part stems from the fact that the student’s vary so much in age. (Our school goes from 6th-12th). Surprisingly enough, even with the high school students, most of the problems were unintentional. Our filters have gotten a lot better, though. It is very rare that something gets through. (I don’t think we’ve had a problem this school year). Also, in the other direction, we haven’t had so many problems with sites being blocked unnecessarily. (For instance, it used to be hard for a high school student to research something about breast cancer, etc). Lastly, there’s just the good old fashioned eyeballing, like you said. I have a monitor on my desk that shows me the students’ screens. The pictures are small enough to protect their basic privacy… I’m not reading their every word. But if something crazy pops up, I can quickly blow up the screen to see it real-size, and control it if necessary.