In a vain effort to stay hip despite advancing age, I recently bought a new toy — something those of us on the cutting edge call a pvp, or portable video player. It fits in my pocket, and it has a screen I can use to watch movies, ballgames, news programs and other videos, or to look at photographs or play mp3 files. I am now fairly assured of winning the subtle, unspoken gadget wars that rage each morning among fellow travelers on TRAX trains.

But I've also entered a realm that is making the war against pornography — especially child pornography — much more difficult to win.

I entered that realm quite unwittingly. I became aware of it only this week after reading a news story in The Record, a newspaper in Hackensack, N.J.

In the old days (which, like all things in the world of technology, really aren't that old), police would arrest suspected child-porn peddlers and seize their computers, usually finding thousands of incriminating digital photos. Today, the criminals are putting photos and videos on their cell phones, their pvps or on flash drives.

Flash drives, for those of you still looking for your computer "on" button, are small portable devices that can store lots of information and that plug neatly into any computer's USB port. Students use them to conveniently store research papers and other assignments so they can edit or print them from any computer.

Because these flash drives can be attached to a key chain or hidden inside something else (The Record describes one found in a ballpoint pen), they present a challenge for investigators, even as they make life a little easier for those who deal in smut.

While I was discovering all of this, the British-based Internet Watch Foundation issued a report this week saying Internet child pornography rapidly is becoming more prevalent and more violent. The report (available online at www.iwf.org.uk), said 60 percent of the Web sites selling such things offer images of child rape. It reports a fourfold increase in such extreme images between 2003 and 2006.

And, despite the complaints often heard about how difficult it is to corral content on a worldwide medium such as the Internet, 62 percent of these sites are hosted right here in the United States.