I have just discovered this awesome extension of FireFox called
adblock, which is filling a gap I have
been complaining about for a long time now.  Blocking images coming from a
particular server is already a very useful feature, but as you may have noticed,
Flash ads are slowly becoming the norm in advertisement, and unfortunately,
FireFox (or Mozilla) doesn’t let you block them.

Nor does it allow you to add Web sites manually to the "blocked" lists, so
the only solution is to view the source, locate the URL of the ad (not always
easy) and alias it to "localhost" in your hosts file.

These days are gone.  adblock does all this and will let you specify any
arbitrary filter on the URI you want.  No more unwanted animated GIF’s or

The Web the way it’s supposed to be.