Adblock Plus for firefox allows you to physically click on a ad etc and block it
How do I block a banner?
You can right-click on any image or frame and choose “Adblock” from the context menu. This will open a dialog where you can tweak the new filter before adding. Feel free to replace parts of the banner’s address by wildcards (* — the star symbol) to make the filter block other banners with similar addresses as well. For more information you can read Writing Adblock Plus filters.The list of blockable items shows many addresses. How do I know which one is the banner?
You can look for addresses that start differently than the address of the page you are viewing. Banners also typically have keywords like “banner” or “ad” in their address. Click an address to make the corresponding element(s) blink on the page (unfortunately this doesn’t work for all types of objects). If you are still unsure, press the middle mouse button on the address to open it in a new tab — there you will definitely see whether it is a banner.