'No!Flash' is excellent- I posted details here-
http://www.homeofpoi.com/ubbthreads/show...rev=#Post232418unfortunately the link to the download site no longer works, but I'm sure you could track down somewhere that's got it.
It not only stops pop-ups, but you can also set it to disable graphics, which makes HOP pages download much quicker, and, best of all, you can toggle between blocking and allowing with one mouse click.
Alternatively, most pop-ups need activeX or javascript to function, so putting your IE security settings on 'high' for the interent zone, will stop most pop-ups (and other malware/spyware/adware etc).