In reply to BrumSparky:
I've used a Wacom Graphire for years on Debian.
In the early days it required a bit of knowledge to get working correctly - On the most recent release of Debian with Gnome 3 it required that I did nothing at all.
Worked out of the box. There is nice little 'Wacom Graphics Tablet' tab in my settings screen if I want to change the way anything works.
No experience of the newer (wireless) offererings, but Wacom support Linux development.
http://us.wacom.com/en/developerrelations/linux/
I would google whichever version of Ubuntu you are using and the model name of the specific tablet you are wanting before making a final judgement.