Ask HN: Parents, how do you keep your kids safe on the internet?

I have a 6 year old daughter and she'd like to get her own computer. She has her own bedroom so if I don't set any rules I think she'd be spending a lot of time with the computer in her own room.

I'd really like to buy her a computer. What I'm concerned about is that sooner or later she'd come across the sites that could be harmful for her.

I don't think using web filters is the right way to go and I obviously can't spend all the time with her in her room.

Those of you who are parents, how do you handle that? Do you limit the time kids can spend on the internet? Do you restrict the computer usage to a common living area where you can follow what's going on?