Slight Hijack Smitty - sorry.
What do you do to limit their access to the wily intArw3bs? I'm struggling with this myself as I have an industrious 8YO who has no qualms about typing in "pimp my ride" at the google prompt.
I would like an entire network based solution, not a single client based one - that way I don't have to worry if he's on my laptop vs. his machine, or my wife's for that matter.
The best I've come up with is setting up a proxy with firewall - and then find/pay for blacklists; similar to what businesses do... I'm not crazy about that idea however due to the maintenance and hassle of keeping it running.
I've played around with "glubble" which is too restrictive - but heading in the right direction...