I work as an network administrator in corporate environment and my job is to handle around 300 Desktops and 5 servers. But my management is eating my brain to block few unwanted websites which can be misused by the employees and waste their time on such websites. Of course I am having SonicWall but few users are using some third party tools to browse those type of websites. At last I got fed up and started researching on web for some new tricks to block the websites. For your information all the desktops are on XP professional on 2003 server network infrastructure. So, coming back to the point, I got a great trick on one of a good flowing forum website.
We can block the websites by editing one of the HOST file which present in every XP professional operating system.
Go through this article here: http://www.geeksbox.com/blogs.php?action=show_member_post&ownerID=3&post_id=5
I hope it works with you if you are doing all steps clearly as mentioned. If you have any issues you can get back to me by replying to this post.