Do I have one - yes, I've had mine for about 2.5 years.
Do I love it - YES...couldn't live without the thing
What can you do with it - it's basically a mouse, but in a pen form. So, you do everything you can do with a mouse, except you've got more control, making things like doodling etc a little bit easier. It still takes lots of practice for things like handwriting and doodling, etc.
Are they worth it - to me it was...I bought it because I didn't like using a mouse (I find them REALLY hard to control since it bumps around the screen - but the tablet, each point on the tablet matches up with a point on your screen, so you KNOW where your pointer will be). It also helps/prevents carpal tunnel in your wrist. Mine was flaring up before I got my tablet and I haven't had a problem since.
Where is the best place to get one - you can get them anywhere. I got mine on eBay, but don't really recommend doing that if you can buy them within your country and don't have to order into your country (ie I'm in Canada, and had to order from the US - I had to pay extra in duty, etc - BUT, when I bought mine they weren't really available locally very much).
So overall - yep, get one. It'll take some getting used to, but once you do, you'll probably never go back - I know I haven't!
