MVPS Custom Host File Instructions
I've been using a custom host file on my workstation for quite a while now. It works really well in blocking all sorts of undesired activity. Of course I only have 3 lines to block specific advertising sites but the potential is endless. Such a small change to my local configuration makes such a huge difference in all aspects of online activity.
If you are familiar with the NoScript or AdBlock plugins for Firefox then you are familiar with the concept of blocking certain domains, URLs or DNS names. Your host file is just an extension of how this works. Only instead of doing it at the application level, it does it at the operating system level.
Any time your machine tries to access a resource on the network, it has to translate that network address from a name to a number. If that process doesn't work (or is told to look in the wrong place) the resource isn't found. If that process is a looking for an advertisement or a nasty script, then that resource fails to load. When that resource fails to load it frees up resources on your machine to load more important stuff, like that article on how to winterize your lawn. Your host file just tells your machine to look in the wrong places for specific resources since any resource at this specific location is known to be undesired.
I use Open DNS at home to block a lot of these sites but this doesn't help when you leave the safety and comfort of your home network.
There are multiple sites out there that help with custom host files but MVPS is one of the best. Please take a look and see what they have to offer.