Today I dragged the tablet down out of the attic. It has survived two moves and seven years of sloppy handling. It has outlived two computers and seven OS upgrades. I surfed to the manufacturer website, discovered the tablet is still actively supported, downloaded current drivers for OSX, rebooted, and it's performing like it came home from the store yesterday. There's even a handwriting recognition feature that I haven't yet played with.
Ironically, my computer is too old to use my 2002 tablet at full efficiency. My only installation issue is that The GIMP for Mac OS X doesn't have pressure sensitivity support, because the underlying X11 environment for OS 10.4.11 won't recognize the device as a tablet (which they fixed in OS 10.5). With a commercial drawing program, I'd be set.
So, I would like to wholeheartedly endorse Wacom for their breathtaking awesomeness. This sort of computer peripheral product longevity is unheard of, and if you have any use for a drawing tablet whatsoever, they deserve your business.