So, two apologies in advance. (1) I've searched, but my search terms weren't great. I just can't come up with the word that I'm looking for. (2) This is a -bit- off-topic from the 'car' part.

I'm looking for a source for a tablet overlay (i.e. pen computing) in 17". I have an old Powerbook 17" that is quickly becoming very obsolete, however I would like to turn it into a tablet. My preference would be for a pen-based system, but failing that I'd consider a capacitive or resistive touchscreen (I'd prefer the former, I think.)

I've looked quite a bit for broken Wacom tablets on Ebay and craiglist, but they're not very common and are expensive when found. This is one of the few places on the internet where I think (a) people would understand my sickness and (b) someone probably has an answer for me. Thanks very much.