Good Gear Guide
In pictures: Free Android apps for BlackBerry Play...
Shazam for BlackBerry PlayBook
Shazam is a Web-based service that "listens" to music and delivers artist and song information, along with a variety of album details and more. It may not be an app you'll use every day, but you'll sure be glad to have it when that song you couldn't get out of your head last week starts playing on the radio again and Shazam identifies it for you. The Android app had trouble delivering album art, and it had some issues identifying lesser known artists and songs, but no comparable apps are available for PlayBook at this time so it's definitely worth a download.
In pictures: Free Android apps for BlackBerry PlayBook, 10 best downloads