Arnold>>> Others have been thinking about that question
PWT Travel have actually produced a "passport/booklet" where they provide stamps whenever you´ve collected a new country.
As you say - is Prague and Prague actually in two different countries? How about Estonia, Latvia and Lithuania vs the old Soviet Union? All the new countries in old Yugoslavia? East Germany, West Germany and present Germany?
PS. I´m at 32 with some of the countries above counted double where applicable. This doesn´t really mean anything in the big run where the likes of Peo Bengtsson and Jörgen Mårtensson have collected well over 120!