How can I stay focus and stay off of non productive websites like social networking, blogs, etc?

I've tried software, but its been so buggy that its no use using it. The software disabled me from sites like facebook, smashingmagazine, lifehacker, and twitter at hours at a time and then open back up for an hour.

Right now, I'm trying an app called Cooktimer, which is set for a 30 minute countdown to do work...and then 2 minutes after that of browsing.

My last choice was either militant force (having someone yell at me for getting off task until I'm almost forced to being fired or losing money)...

I'm trying therapy, which my therapist says i may have a big addiction to the internet, and tech toys, which keeps me unfocused on stuff i need to do...and may need some help on that...

Does anyone have ways of not randomly going to facebook when you have work to be done....

Thanks