The Yahoo! Companion toolbar has added an optional popup blocker that offers different features for dealing with popup window advertising.
The new Yahoo Companion Toolbar (only available for the IE browser) PopUp blocker is quite similar to the Google Toolbar’s popup blocker. Both must be a huge threat to the popup killer download industry. Both toolbars allow you to choose to allow popups on certain websites and trackrecently blocked popups.
Download and try the Yahoo Companion Popup Blocker .
Or, try the Google Toolbar which also offers a free popup blocker