I have just tried a Wacom Bamboo tablet on my Ubuntu 12.10 machine and it worked perfectly. Using the tablet as a large touch pad to navigate the Gnome Shell desktop is quite fun indeed. You may use the touch pad to navigate the desktop and double tap on the tablet to open a folder or run an application. Drawing with the stylus with the Krita drawing application is very manageable; I managed to create a simple artwork very easily using that application. Drawing naturally with a pen takes a bit getting used to as the way the pen works with the tablet is different than using pen and paper; but once you get used to the way the graphics tablet works; you can create some awesome artwork as well as easily retouching photographs and writing letters using handwriting on your PC. There is a nice online handwriting recognition demo here that will enable you to enter text via the pen and have it translated into text. This is useful if you wish to test out your writing skills on your tablet. This demo actually works very well with my bad handwriting.
To the right is the artwork I created with this tablet using the Krita software. I created the rolling hills with a set of brushes; these were painted on the canvas and then I had my hills with trees on the horizon. This is a primitive first try; but I could improve with practice.
This is the model of tablet I am using: http://www.ozgameshop.com/tablets/wacom-bamboo-pen-and-touch?utm_source=google&utm_medium=shopping&utm_campaign=google+shopping+data+feed+(23/11/2012)&gclid=CN_f_NPm5LMCFQE5pgod_kIArQ. This model works perfectly on Linux and Windows.