Google Pop-up Blocker:

The Google Pop-up Blockers stores a whitelist of the websites that pop-up windows are allowed to lunch, as opposed to a "blacklist". Click the pop-up blocker button on your browser's Google toolbar to add this site to your whitelist as highlighted in Figure 1 below (The whitelist is never actually displayed.). Your Pop-up Blocker counter will be changed to read "Site popups allowed" as in Figure 2 below.

(Figure 1. Pop-up is not allowed for the site)

You may remove the site from your whitelist anytime by visiting the site and clicking the pop-up blocker button again. The button will change from "Site popups allowed" to block counter.

(Figure 2. Pop-up is allowed for the site)