Kathleen Anderson wants pop-up advertisements gone from the Net. As chair of a state government committee, Anderson is charged with ensuring state-run Web sites become accessible to people with disabilities. She reviles the use of pop-up ads on mainstream Web sites such as AOL.com and Netscape because the disruptive ads -- which appear on Web pages spontaneously -- often confuse a blind person, for example, who relies on a screen reader to hear content rather than see it on Web sites. "Often they pop up two or three at a time and get in the way of screen readers so that the text gets all jumbled," Anderson said. Although Anderson's feelings are pegged to a specific cause, they are echoed widely among consumers on the Internet, which is increasingly becoming littered with such jack-in-the-box ads. Heavily visited sites such as Real.com, MSNBC.com and CNN.com are throwing up the ads in efforts to improve declining response rates for banners and, in turn, squeeze more dollars from advertisers. A pop-up ad, which typically takes up a quarter of a page, forces consumers to either act on a promotion or click a button to close the window. To combat this, Anderson and others are fighting back with software and self-styled tricks to keep pop-ups from their screens. Software including Pop-Up Stopper and Banner Catcher has emerged to help consumers fight the advertisements. "Many consumers are tired of the unwanted pop-up windows on their computers that can't be closed or avoided without shutting down the computer," said Matina Fresenius, chief executive of Seattle-based Panicware, which publishes a 30-day free trial of Pop-Up Stopper online. The program, which only works with Microsoft's Internet Explorer, prevents pop-up windows and gives consumers the choice to view certain ads. Fresenius said she got the idea for Pop-Up Stopper after she received numerous complaints from parents about the reoccurring appearance of pop-ups containing "adult material" on MP3 sites that kids often visit. Since Panicware launched the software nearly a month ago, it has had almost 100,000 downloads, Fresenius said. A program dubbed Banner Catcher, from Softica Solutions, lets consumers either control ad windows automatically or zap ones they want to discontinue in future visits to a site. The shareware software works on Internet Explorer and AOL Time Warner's Netscape running on Windows 95, 98 and NT operating systems. The popularity of such programs could be linked to the rise of pop-ups on prominent sites. According to search site Top9.com, AOL.com is ranked No. 1 for using pop-ups, followed by Netscape.com, Real.com, Jobsonline.com, Msnbc.com, CNN.com and Time.com, which were all tested using Internet Explorer 5.0 and Netscape 4.7. AOL.com, for example, launches a pop-up promotion urging consumers to sign up for AOL 6.0 when consumers immediately visit the site. Top9.com gives consumers advice on how to prevent the ads, including hitting the "control" key plus "W" to knock them out immediately. Netscape users can also prevent pop-ups by changing their browser preferences to eliminate JavaScript. "People loath pop-ups because it clutters their desktop and forces them to do work to clean them up," said Jason Catlett, president of anti-spam group Junkbusters. "It's a major reason that people start using products for filtering banner ads." But such software can be unreliable and even ineffective to a new form of online marketing used on such sites as PassThisOn.com, which launches multiple browser windows as people exit the site. Catlett also suggests turning JavaScript off in browser preferences, but it may also make navigating various Web sites more difficult, he said. "That may be a small price to pay for the peace and quiet." But often consumers who are annoyed by the use of pop-ups simply refuse to return to the offensive site. "I just don't go back to sites that use them," said Anderson, who has set her browser preference to ask her if she wants to receive JavaScript in a pop-up window. She has also installed software to prevent pop-ups. "Web masters can find other ways of getting their message across, the advertising or marketing, rather than taking control of your desktop, which is what they do," she said. Catlett added: "The large media properties are already acutely aware that they are trying the patience of their users with pop-ups. But there's a limit to users' patience." Find out how the Internet is revolutionising the economy at the E-commerce Special. Have your say instantly, and see what others have said. Click on the TalkBack button and go to the ZDNet news forums. Let the editors know what you think in the Mailroom. And read other letters.