Few things online annoy me more than pop-up ads and windows! And I know I am far from the only one. In fact, I remember one survey-thingy a few years back where pop-up ads were voted the #1 nuisance on the Internet. It wasn't long after that they quit being so popular, as many of us simply quit going to sites that employ them. But make no mistake about it, pop-up ads still exist, and while they may not be as prolific as they once were, they are still a pain when you do encounter them.
That is, unless you have a good popup blocker. And while many browsers now have built-in blockers, they do not always catch them all - especially the more popular browsers - as black-hat advertisers never stop developing ways around them.
Make sure your online enjoyment is not hindered by these ugly tactics. Follow the link above for more information on how to protect your computer against unwanted pop-up ads.