From the press release:
OverDrive (www.overdrive.com), the leading global distributor of audiobooks and eBooks to libraries and retailers, today announced the public beta release of an audiobook app for BlackBerry® smartphones. OverDrive's BlackBerry audiobook app enables the wireless download of MP3 audiobooks from more than 10,000 libraries and major online retailers, including BarnesAndNoble.com, BooksOnBoard.com, and Borders.com. To download the audiobook app for BlackBerry devices, including the BlackBerry StormTM and BlackBerry CurveTM, visit http://www.overdrive.com/software/omc. BlackBerry users can also visit http://search.overdrive.com on their devices to find libraries that offer MP3 audiobook downloads.
Overdrive have also released similar apps for Android, Mac, WindowsXP, and Windows Mobile. You can download them here.