WWW- Podcasting, that baby medium, is suddenly home to a lot of adult content. Introduced to a mainstream audience just last month, the technology-radiolike programming for your iPod-that was once the chaste province of “Geek News Central” and “Knitcast” is now reddening faces that sport those trademark white earbuds. “No matter what the technology is,” says Andrew Leyden, founder of podcastdirectory.com, “sex finds a way to get involved.”Story continues below ? advertisement

At podcast.net, the No. 2 most-searched-for term (right between BBC and NPR) is porn. At Leyden’s site, six of the top 20 shows are adult-oriented. And at Apple’s behemoth iTunes store, “Open Source Sex” is No. 11 and climbing. From the breathy erotica of “Pod Porn” to the subdued interviews of “SexGeeks,” mature programming for the iPod can be titillating, educational or sometimes both, and it is spreading fast.

Part of the appeal is populism. Just as indie-rock podcasts see themselves as the antidote to rigid corporate playlists, sex-themed shows are proudly amateur. Anyone with a microphone, a PC and some privacy can produce one. “You don’t need big breasts or big advertisers,” says Violet Blue, the host of “Open Source Sex.” “It’s the ultimate democratic tool for sex education.”

Parents are less pleased, in part because filtering software is useless against the new technology. But they can take heart: the next Next Big Thing is religious programming (“Catholic Insider,” “Pray-station Portable”). It’s known as-what else?-godcasting.