And there are drawbacks to the audio-only approach. While Oracle hopes technologists will find its podcasts useful, "there's no visual sample code or screen shots to accompany the MP3 files," Kestelyn says.

One of the best things podcasting has going for it is that it's free--even though some listeners might be willing to pay for the right content. A recent study conducted among young European consumers by Forrester Research found that 46% of 16- and 17-year-olds would consider paying for podcast content. However, only 33% of the teens surveyed said they would accept advertising as a necessary evil to subsidize content.

For all the buzz podcasts have created among the tech savvy, the technology is still relatively unknown. The Yankee Group estimates that by the end of the year, 41.6 million consumers will own a digital audio player, and there will be more than 10,000 businesses and individuals publishing podcasts. Currently, however, less than 1% of digital audio player owners actively download and listen to podcasts, the Yankee Group says.

Momentum is building. About 600 subscribers download Oracle's podcasts every 24 hours, Kestelyn says. FeedBurner offers more than 15,000 podcast RSS feeds, up from less than 1,000 in January. It now has 450,000 podcast RSS feed subscribers, up from 150,000 in June.

Podcasting soon won't be limited to MP3 players. Melodeo Inc., which gives cell-phones users the tools to download music, says it will make it possible to get podcasts from cell phones starting in September. Melodeo will offer software called Mobilcast that signs onto and searches Podcast directories using search criteria set by the user to find new content. Mobilcast will download and store podcasts on phones to be listened to when the user chooses. The software converts the MP3 format, unreadable by the mobile phone, into files created in aacPlus, an audio-compression technology. Mobilcast initially will support the Symbian operating system, followed by a Java operating system version.

Meanwhile, more and more people are learning about podcasting from a variety of sources outside of IT and music. Many major media outlets deliver news podcasts. Purdue University says it began making replays of class lectures available in podcasts last week. Earlier this month an astronaut with NASA sent the first podcast from a test flight on the space shuttle Discovery. And religious groups are using podcasting as a virtual pulpit. One of the more successful examples is Tim Hohm, a senior pastor at Central Assembly in El Sobrante, Calif., who delivers a 15-minute inspirational message twice weekly called RevTim. Subscriptions to RevTim have grown to 6,000 since the podcast was launched in December, ranking it among the top 50 most popular podcasts on Podcast Alley. Forrester Research estimates that by 2010, more than 12.3 million listeners will synchronize podcasts to their MP3 players.

Such huge loads of information, however, can amount to mounds of garbage unless listeners can find things they actually want to hear. For those looking to advertise through podcasting, the Yankee Group advises that podcasts should be built around focused topics that appeal to specific demographic groups. Subscription-based models have been considered by some podcasters, but in the near future, it's likely that advertising will be the principal revenue stream for those looking to profit from podcasting.