Nielsen//NetRatings announced today that 6.6 percent of the U.S. adult online population, or 9.2 million Web users, have recently downloaded an audio podcast. 4.0 percent, or 5.6 million Web users, have recently downloaded a video podcast.

These figures put the podcasting population on a par with those who publish blogs, 4.8 percent, and online daters, 3.9 percent. To put this in perspective, though, Nielsen notes that podcasting is not nearly as popular as paying bills online, 51.6 percent, or online job hunting, 24.6 percent.

"The portability of podcasts makes them especially appealing to young, on-the-go audiences," said Michael Lanz, analyst, Nielsen//NetRatings. "We can expect to see podcasting become increasingly popular as portable content media players proliferate," he continued.

Young people are more likely than their older counterparts to engage in audio or video podcasting. Web users between the ages 18 and 24 are nearly twice as likely as the average Web user to download audio podcasts, followed by users in the 25-34 and 35-44 age groups, who were also more likely than the average Web user to do audio podcasting.