I would think your level of control would be dependent on what the stamps contained? and what they are used for? Do you have stamps with signatures? or for approving things? (like approving an inspection) If so, you may want to create an ID # for each stamp and create a log as to who has which stamp (and who's responsibility it is to control their stamp).
Back in our old days of hardcopy document control, we had a system something like what AndyN said above. Our stamps were simply "Controlled Copy", "Uncontrolled Copy", "Draft", "Copy", and a big old "Obsolete" stamp. We didn't create ID #'s for those as they are fairly basic stamps.