Creating a pen tablet like Wacom Bamboo

I am newbie in Arduino, first idea that came in my mind is to create a tablet which will take pen input and draws on screen. Can any one share there thoughts/ articles that can help me in getting started for things like : Hardware requirement...

screen is that a PC screen or an Arduino (controlled graphic) screen?

DO you want to emulate a mouse? or do you want to emulate the bamboo app?

I am looking for a external pad, where i can write. Not sure if such thing exists for Arduino. My objective is to write on the screen, for applications like paint, photoshop (ink)