Yes and no. It's relatively easy to set up an HTTP proxy (and I can think of several ways it could be made plug-and-play for non-geek parents). However, enforci

Yes and no. It's relatively easy to set up an HTTP proxy (and I can think of several ways it could be made plug-and-play for non-geek parents). However, enforcing the use of the proxy on the client is basically impossible. Mandatory group policies come close, but if the kid can get admin they can just turn it off (and lets face it, they've got physical access to the client, if not the proxy server). Probably won't stop parents paying for it, though :)