You REALLY should check out opendns.com before you pass judgement on it, as tennis shoe and crow really do taste terrible.
As far as implementing DNS goes, it is extremely simple:
Preferences > network > select lan interface (eth1, airport, etc.), in the DNS box enter 208.67.222.222 and 208.67.220.220 (put a comma in between the two numbers):208.67.222.222, 208.67.220.220
That's it!
Router blocking is great for keeping them off mail sites like gmail, pirate sites, proxies, blocking ports, protocols, etc. (things that may not be blocked normally be filtering software, of course kidsgogogo is configureable also.
A vnc server solution allows you to view their screen with them being unaware they are being viewed (as long as you don't take over their mouse). 🙂
Besides, never underestimate the computer IQ of the people reading these posts either. I simply try to offer accurate information as understandable as I am able to explain it and let the readers pick and choose as they may and make rational decisions as they see fit. I really have not investigated Apple's solution so I'm not qualified to pass judgement on it anyway, but I can tell you the kids got around Tiger's solution almost immediately, it was no challenge to them at all. They have been trying to hack on the kidsgogogo for some time now, unsuccessfully I might add, so I know it's a great solution, at least in my case. BTW it does have free trial period also to see if it is right for you.
An effective solution is going be different in almost every case, depending on a child's age and computer skill level, in fact, nothing short of locking a computer in a safe and welding the door shut may be good enough to keep some kids from hacking around your safeguards. I know a few kids that speak binary better than I do, It is a good thing they are good kids, that as far as I know, are responsible citizens that don't need all that monitoring.
If you think I like having to monitor someone's computer activities, then think again, my hours behind the keyboard are plenty long enough without that.
Best,
Kj