I just got a Nexus 7. Since I'm currently learning 3ds Max, I was wondering, can I use this tablet as an input device for 3ds Max? I would like to be able to use it with a pen to draw and animate my models.
The Nexus 7 has a capacitive touch screen and doesn't have a digitizer - so it only can use a stylus instead of a digital pen. The accuracy of a stylus is worse than of a digital pen - it can't for example distinguish pressure levels.
This will not work as a fully featured graphics tablet though - think of it like a touchpad in a laptop.
You could use your Android device as a touchpad for PC/Mac. Search Android market for "Touchpad", there are several applications available. This being said, a dedicated real hardware touchpad with a pressure-sensitive stylus will work much better.