If parental control is truly the main issue, face detection algorithms that also assess your age could be a solution [1], but then again, it seems like Samsung is owning the patent for this [2]. Oops!

Sources: 1. http://www.sync-blog.com/sync/2012/04/how-old-do-you-look-fa...

2. http://www.google.com/patents/US8218080