I have to say, I've been studying e-drawing at TAFE and these things are amazing, won't go into much detail, but I bought myself one and its the best thing i have ever bought for my PC
Dot have a picture on the PC right now but heres the website anyway
Wacom Australia Home | Wacom Australia
These things are the most amazing things, I myself use an A4 Intuos 3 at TAFE and an A5 at home, these tablets and pens in particular have a pressure sensitive pen offering 1024 levels of pressure this means (in painting programs such as photoshop) you can use brushes with variable pressure. Tilt sensor, programmable touch strips on either side and is ergonomically designed, it can and is used INSTEAD of a mouse entirely, this thing really is the ultimate tool when drawing on computers. Will probably get some pictures of work and the tablet up later, but its a bit late now