Adblock plus is a Firefox plugin for you to block the unwanted ad in the web site. After installing Adblock Plus, you may set your ad blocking rules manually or you may just subscript to the standard filter list from the subscription provider, it cover most of the ad source from that partical area.
Besides that, you may also add the ad to block which is not in the subscription list by simply right click on the ad banner and click on AdBlock Image; or click on the small block tab on the top of the ad image.
Immediately you will see the page without any ad. You may also use this application to block the ad in Hotmail and Yahoo Mailas well.