URL filtering or parental control in Airport Extreme

With all the kids unfriendly stuff on the internet from one side and the large number of internet connected devices on another side it would be real nice to have the ability to setup parental controls or URL filtering (similar to FoxFilter) on the wireless router itself. This was you could use any OS, iPhone, iPad, etc.... and control user access to the internet consistently across all of those devices.

I am surprised this is not yet a main advertized feature of the airport. To me this is more important than ability to connect HDD or printer to the Airport.

Apple, any ideas on when this would come as a firmware update?

Same thing for the directory server - I would love to setup directory of users and passwords on the router so that I dont need to go around all of my laptops and change passwords for each family member to keep things consistent.

Other folks on this forum - any recommendations on how to solve this problem?

I do not want to run a dedicated machine and eat up electricity just to run a filtering proxy server or LDAP server.