It took a couple years and a growing curiosity, but I’ve hopped on the bandwagon and, after many “pokes”, have gotten swept up by the Facebook frenzy.

Unlike other social networking sites I’ve joined and dabbled with in the past, Facebook has impressed me the most in terms of delivering simple yet incredibly effective mechanisms for connecting with people online. By all accounts, I can say I’m one of the many users bumping up the latest spike in traffic to the social networking site.

One of the more intriguing trends I’ve noticed with my own personal use of Facebook is that since I signed up, when I look in my email inbox (my regular email, not my list of messages within Facebook), there is a disproportionately large – and growing – number of emails coming from Facebook. And it’s not spam, these are messages being sent by my friends through Facebook.

I don’t know if this is something the Facebook creators have in mind or have on their radar screens, but this model of communication is on the path towards effectively creating a filter of sorts to weed out spam.

In this model, Facebook acts as the gatekeeper – when you add a friend to your network in Facebook, you can decide how you’d like to let people contact you. In effect, Facebook gives you a means for setting up an authentication system of sorts where you give people a token pass to get in touch with you. Anyone can send you an email so long as they have or have access to your email address. But through Facebook, you will only be contacted by people whom you’ve already indicated are within your circle of trust.

This could be one of these unintended uses or side effects that could lead to an innovation (read: new model of fighting spam) that I’ve written about in the past. It’ll be interesting to see how, if at all, this type of shadow communication system evolves.