PopUp Killer. Billed as "the original and most powerful popups-destroying machine ever created," this free program (which got a four-star rating from ZDNet) purports to close nasty pop-up windows before you even see them--and even removes the persistent GeoCities boxes. It works on the Internet Explorer, Netscape Navigator, Opera, and NeoPlanet browsers.
Pop-Up Stopper. This freebie from Panicware is aimed at Internet Explorer users, and says it saves bandwidth by preventing extraneous windows from even loading, let alone showing up.
And, here's a list of free and fee based downloadable programs:
This was first published in July 2003