My home computer network has a Linksys router.. Others I am told are similar.
I found in router setup labeled :"access restrictions" 10 pages of different types of limitations you can put into the system. each page has about six URL blocks and about 10 or so keyword blocks. You can enter times when the restrictions are in place, or internet is shut off. Most the time the kids are up to no good when you are not watching, late at night. IF you enter the IP of each computer manually, you can make it apply just to thier computers.
Example.. "chat", "forum", "email" "screw" "X"
Sneaky kids, all the kids sites has chat rooms.. zetapets.com webkinz.com meez.com and others, so the keyword block works. My daughter had her older sister here with her, she went home with a bunch of boys phone numbers. BOYS? men, old men? I trusted them to a point.
AND them typing PIR (parent in room) or if the kids swap screens as you walk up means big troubles.
THIS is so simple to be able to block things in the router anyways.. much simpler than I thought, just a few clicks.. remember to change the default password and not to save it in the wallet thou, or the kids will block you out.
My point being, you don't have to be a computer guru to use the blocks. Easy to do. And I never knowed it was there before.