If you're a parent, you probably know how much of a pain it is to keep your kids off the Internet and doing whatever it is they're supposed to be doing (that car isn't washing itself, champ). This keyfob from Best Netguard solves all your parenting problems (yes, ALL OF THEM) by letting you turn off the a PC's internet access remotely. That way, you can be sure that your kids aren't IMing or surfing when they're supposed to be doing homework.
Asking them nicely to not use the Internet never works, because they're lying little bastards who will take advantage of you as soon as your back is turned. They learned that from you, after all.