Most popup blockers allow you to either selectively allow popups from some sites or temporarily disable their function altogether.
Here are some links that will help to configure the most common popup blockers...
Google Toolbar
Yahoo Toolbar
AOL Toolbar
Microsoft Internet Explorer (Windows XP Service Pack 2)
Firefox
Netscape
Safari
Pop-up Stopper
Popup Manager (for Internet Explorer)
Starware Toolbar (for Internet Explorer)
Norton Internet Security
With virtually hundreds of popup blockers on the market today it is impossible to provide links to all of them. For instructions on other popup blockers not listed above, please refer to your popup blocker manufacturer's manual or website.