Okay beta testers, it's time to check out another Android application.  This time it's for a social music service called Rdio (pronounced r-dee-o).  If you haven't heard of the service, that's alright.  Neither did we until this week.  Looking at their website, we learn that Rdio plans to help change the way we discover and share music as well as the way in which we access it.  Rdio offers unlimited, on-demand access to five million songs  from players like EMI Music, Sony Music Entertainment, Universal Music Group and Warner Music Group.  For a monthly subscription fee, users can listen to as many songs as they want, anytime and anywhere.

Rdio also provides awesome tools in personalized recommendations for new music based on your music tastes and listening behavior.  It's also possible to create on-demand radio stations based around favorite artists, replicate your iTunes library, and collaborate on a shared playlist. All kinds of cool stuff from some of the minds behind imeem, Skype, and 20th Century Fox.

Currently, Rdio is an invitation-only paid preview program.  There are two flavors available to choose from: Web and mobile access (including syncing music) for $9.99/month or web-only access for $4.99/month. Thankfully, Rdio was gracious enough to provide TechCrunch with 2,000 beta invites.  If you're running Android 1.6 or higher, you are advised to click the link to sign up!