Pop-up technology improves

According to news.com, Google's tool bar, which was confidently touted as a firewall against pop-ups has been tunnelled under by the ad companies.
Blocking software usually detects an HTML command known as "openwin" for opening a new window. However, a new breed of pop-ups avoid that command. Some advertisers are sending pop-ups through a "user initiated command" triggered when people "mouse over" an object on the page.
Another technique uses JavaScript commands, and gets around pop-up blockers that don't block user initiated commands like Google and Yahoo.
According to researcher Nielsen NetRatings, pop-ups have only become more prevalent after software appeared to kill them. Their number has increased nearly six times since 2002. A number of big publishers use pop up ads.