MySpace and Facebook continue to lead the pack as the two most popular social networking sites but for the first time, it also seems fairly clear that Facebook will soon overtake MySpace in overall usage, particularly as it offers a richer overall platform powered by a large and vibrant community of 3rd party application developers.

Facebook’s open architecture takes this concept to a whole new level and allows existing Web businesses to plug directly into their social infrastructure with their own Facebook applications. These apps can be standalone or integrated across the Web from Facebook back to the online business. The interest in integrating with Facebook has been high.  As a result, over 5,100 Facebook applications have been developed to date that run the gamut from games and fashion to education and productivity software.

[Via ZDNET blogs]