Facebook ban

I must be the most unpopular guy in the office at the moment. I've just gone and banned facebook.
don't get me wrong, I'm a big fan of facebook. I love its interface and all the cool add ons. I've been having a blast since I joined a month ago and have been reunited with guys I haven't heard from for 20 years. Its highly entertaining and addictive, and thats where the problem lies.
I just can't have staff mucking around on facebook and checking their friends messages and statuses every 10 minutes and not doing work. Its distracting and highly unproductive. Part of the blocking of the website is to stop myself from being distracted too.
As I said before, I think its great, I'll still check it at home in my own time, just not on company time.
sigh now back to work.