I was just wondering if there are any programs (maybe free) that can block al porn sites from being looked at (online)... thanks :)

Yes, there are several, but I don't endorse any of them as they block sites based on THEIR agenda. For example, one may block all porn, but it may block barbie.com as well (proven by experience) or any references to what THEY deem offensive.

Netnanny is one name that comes to mind, although I have no experience with it whatsoever.

And don't forget to set the internet settings in your browser! Exploder, Mozilla, and Opera ALL have built in blocking or "Parental settings" that can prevent offensive sites.