Apple said subscriptions from the new iTunes Podcast Directory surpassed the 1 million mark within two days of being offered as part of iTunes version 4.9, released Tuesday, according to TechWeb News. Apple's Steve Jobs said yesterday that the launch would take podcasting mainstream.

"Our servers have been swamped with a stratospheric increase in traffic. In fact, downloads have increased tenfold as a result of the iTunes 4.9 launch," ElectricNews.net quotes a Southern California Public Radio station KCRW management consultant as saying. "iTunes has done what possibly no one else could have accomplished, propelled Podcasting into the mainstream."

The iTunes upgrade has tools for finding, subscribing to, managing and listening to the podcast online audio files, the content of which can range widely - from comedy to politics, advertising or rants. Podcasts can be downloaded from iTunes to Apple's the popular iPod portable music player - or to personal computers. The company offers access to more than 3,000 podcasts.

Pew Internet and American Life research suggests that some 6 million Americans - nearly a third the 22 million estimated to own MP3 players - have listened to podcasts.

Market Watch reports that shares of Apple rose 49 cents to $36.86 in late afternoon trading yesterday.