So I drafted a post about two years ago at this point which essentially said facebook is slowly replacing the blog. It's been slowly filling and expanding what blogger was providing. Anyway, one big way facebook has been increasing it's breadth is by becoming the defacto login / user account piece for a number of web applications. Essentially 90% of new web (i.e. mobile) sites / applications offer a single sign-in option with Facebook.
Case in point Spottily. if you like music you should really check this out. You can think of it like Pandora but with greater integration into your existing desktop audio library, social networking (i.e. Facebook), and sharing.
Here's a playlist I set up... enjoy at your next party!!