I bought a Wacom Bamboo tablet to use for taking notes in lectures. I have had it for nearly two years and it has been really good. I haven't really used it on a Mac though, because I have only just purchased my macbook pro on the 3-Mar-11. I used the tablet in Microsoft OneNote on Windows.
Last night, I downloaded the trial version of Curio and it appears to work. The Mac picks up the Wacom Bamboo immediately as soon as it is plugged in. The mouse that comes with it is less sensitive than on Windows though, but the pen seems to work fine.