Bamboo tablets are great for those who enjoy sketching or those who want a little more control with photo editing. The reason I purchased one was because I was tired of writing things out on paper, scanning, then adding the scans to photos with Photoshop.
The tablet plugs into a usb port on your computer. I'll admit that using the pen and "writing" takes a little practice. It's best to keep your eyes on your computer screen while writing. The letters seem to flow better that way. Overall, I think it's a great tool.
Have you ever worked with a tablet or are you thinking of purchasing one?