Wow! thanks, everyone, for your quick replies.
Our boys are not allowed to have computers in their bedrooms. At this point in time, we have ONE family computer set up in a room where everyone can see what they are doing. I thought that would be enough. But you know, as they get older, they get wiser. and so if there's a couple of boys circled around the computer, Mom can't see thru the backs to see what's going on........... Hmmmmmmmmmmmmm. I believe THAT is going to stop too!
The other thing that those of you with younger children will want to be aware of is that you may have the strictest controls possible on them at home. But when they go to their friend's house and their friend has a computer in their room that no one is monitoring, it is very easy for them to get on at that point and do whatever they choose. That's how Keith got a MySpace account that I didn't know about until this morning
I'm going to check out these filtering programs you all have shared with me. Thanks again.