NEW YORK -- It's a Web surfer's dream: software that automatically ends the distracting stream of pop-up and banner ads.

Though none of the eight products I tested suited all my needs, a few did a decent job of killing many ads without inadvertently zapping too many useful items.

So say goodbye forever to those annoying ads featuring half-naked women pitching X10 wireless cameras and those unsolicited travel deals from Orbitz.

For blocking pop-ups, it was a toss-up between the $18.95 AdsGone from A1Tech Inc. and the free PopUp Killer from xFX JumpStart.

Both got rid of most pop-ups, though zapping them is the easy part. In fact, of the seven products that promised to block pop-ups, all but the $12.95 PopUp Eraser from SK Lab did a good job.

The difficult part is knowing when a pop-up is useful. So I subjected the software to 16 sites that had useful pop-ups, including television listings, photo galleries, animated features and results of Web surveys.

Neither the free nor the premium ($19.95) versions of Pop-Up Stopper from Panicware Inc. were able to recognize the useful pop-ups, though they sometimes allowed me to override the zapping by holding down the "ctrl" or "shift" key.

Zero Popup, $19.95 from Tooto Technologies, gave me the pop-ups using a similar override. But its banner-ad filter zapped what was supposed to be inside, giving me an empty window I had to then manually close.

The $29.95 AdSubtract Pro from interMute Inc. didn't even provide an override key.

Though AdsGone was good about recognizing useful pop-ups, it wouldn't let me open pages in a new window by right-clicking on a link.

Normally, I open message board postings and news articles in new windows so I don't have to keep hitting the back button and lose my place. Unfortunately, AdsGone treats those windows as pop-ups.

With PopUp Killer, I had to download a set of filtering rules or create my own. I also had to manually add pop-ups that slip through those rules. After about a day, though, the software blocked most pop-ups.

An optional "smart engine" -- with a choice among 21 levels of aggressiveness -- took care of new ones as they, well, popped up.

PopUp Killer was a bit more aggressive than AdsGone at zapping useful pop-ups. The software, under my configuration, looked for "ads" and "popup" in the Web address, thus killing useful sites that contained those words.