Break out your iPods: Harry Potter (search) is going digital.

J.K. Rowling (search), once publishing's greatest holdout against the computer age, has made all six Potter novels available for audio downloads.

In a message posted Wednesday on her Web site, Rowling said she was concerned about online piracy, included bootleg editions for which the original text was altered.

"Many Harry Potter fans have been keen for digital access for a while, but the deciding factor for me in authorizing this new version is that it will help combat the growing incidents of piracy in this area," Rowling wrote.

"There have been a number of incidents where fans have stumbled upon unauthorized files believing them to be genuine and, quite apart from the fact that they are illegal, the Harry Potter content of these can bear very little resemblance to anything I've ever written!"

The digital audiobooks are being released by the Random House Audio Trade Group, her current audio publisher. They can be purchased through Apple's iTunes store, for prices ranging from $32.95 for a single book to $249 for the whole series, which, according to Random House, includes a "full color digital booklet" and "previously unreleased readings" by Rowling.

Neil Blair, a lawyer with Rowling's literary agency, said Wednesday that there are no current plans for Potter e-books.

Rowling's fantasy series, most recently "Harry Potter and Half-Blood Prince," has sold more than 200 copies worldwide in print editions and more than 5 million as audiobooks, narrated by Grammy winner Jim Dale. But up to now the author had only permitted paper and traditional audio releases, making her work a favorite for online pirates, although illegal sales are believed to be relatively tiny.

Helped by the iPod boom, digital audiobooks are already one of publishing's hottest sectors, with sales nearly quadrupling between 2001 and 2003, to more than $18 million, according to the Audio Publishers Association.

"It's very exciting that an audiobook both critically acclaimed and commercially successful is finally available to the very broad audience of people who enjoy downloading," says association president Mary Beth Roche.

Also Wednesday, Rowling said on her Web site that she was concerned by a wave of Potter merchandise with fake autographs for sale on eBay.

"As far as I could tell on the day I dropped in, only one of the signatures on offer appeared genuine," she wrote.

"There seem to be a lot of people out there trying to con Harry Potter fans. The same is true in respect to the huge number of unauthorized Harry Potter e-books and audio digital files that users of eBay have offered for sale to Harry Potter fans," wrote Rowling, who accused eBay of refusing to take responsibility for what it allows to be sold.

eBay spokesman Hani Durzi said Wednesday that Rowling is part of a copyright protection program offered by the online auction giant that allows members to report problems. Durzi estimates that eBay has 55 million listings at any given time and says that "it's the responsibility of the copyright owner to report any listings that violate their rights."

"When they do, we take those listings down immediately," he said.