Sorry, busy learning how to compile some stuff in my Debian VM and a bunch of other crap, so I very quickly skimmed the post, but:

What's the point of 'age verification'? Smart phones, even the geeky N900, presumably are one-person devices. It's not like we run these things with different accounts and parental controls. Either way, without being an utter PITA for the average user (regardless of age), how would it do anything, other than say "Are you over your legal age for viewing pornographic/adult material? [Y/n]" "Are you aware of the laws pertaining to such material in your area? [Y/n]"?

Is it basically just making the user spend some extra time clicking through yes/I-understand/I-agree statements, or is it more complicated than that? And if it is more complicated then that, is it worth doing it at all, if the users who do want to view such material, above or under the appropriate age, will still do their best to get through whatever inhibitors you put in their path?