There are some things more irritating than having a surprising window pop-up when you visit a new Web page. These appropriately named "pop-up windows" usually contain advertisements and can come out either in front of or behind your current browser window. Either way, they can be a trouble.

If you are Windows user, you can make use of a Web browser like Firefox that offers you the option of blocking pop-up windows. You can also download the Google Toolbar, which will block pop-ups. If you are a Mac user, simply choose "Block Pop-Up Windows" from the Safari menu, in Safari, the default Web browser.