I love this application, Graffiti on Facebook and that's all I feel like saying right now!
But, being the talkative person that I am, I now feel like saying more about it... Well, the application is simply great chiefly because of its simplicity. We have just three parameters to work with. Colours; 180 shades to choose from, Brush size and Brush's transparency and viola there you go! :)
One sweet part about is that once you're done you can press the 'play' button and see your graffiti by an invisible hand ... Basically it fast forwards your drawing session.
So if you are one of the artistic ones, do try this ... Happy Graffiti-ing :)