Wednesday is Facebook's 5th birthday. If you're not one of the social network's 150 million members, perhaps it's time to join the party. Or maybe not.

Mark Zuckerberg founded Facebook as a website for college students, but it quickly spread to the general consumer market as a way to connect with friends and share community. Now professionals are using it to network, businesses are using it to engage with customers and partners, and politicians are using it to get elected and promote their agendas. You can read more about the evolution of Facebook in Zuckerberg's post to the Facebook blog.

Those who've been with Facebook since its beginning have seen a lot of changes in the last five years, and Facebook has posted this retrospective slideshow of how the site has evolved. 

But not everyone is happy with all the Facebook changes. They claim that what started out as a useful tool for connecting with others has become so bloated with gimmicks and silly applications that it is simply a monumental time-waster. I'll admit, keeping track of my friends and family's thoughts and actions on a daily, hourly, or even minute-by-minute basis can be addictive—and mostly nonproductive. And I can see why some businesses are actually banning employees from using Facebook—at least at work—in order to increase user productivity.

I don't think social networking sites like Facebook will be going away anytime soon, but the debate over whether this model is a useful tool or simply a foolish waste of time will go on until people and businesses learn how to leverage the platform for productivity, collaboration, and commercial gain. Can a "one-size-fits-all" application fit for both personal connections and business needs? It will be interesting to see where the next five years take Facebook—and how many of us will go with it.  Where do you think it's headed? Let me know your thoughts in the comments section below.