We took many different kinds of transportation on our journey. In no particular order: commercial jet airplanes, private buses (Poland), public buses (Croatia, Poland, Vienna), streetcars (Warsaw, Zagreb, Vienna, Prague), taxis (Dubrovnik, Vienna, Prague, Warsaw), private cars (Sopot/Gdansk), ferrys (Croatia), a catamaran ferry (Croatia), river cruise boats (Austria), a rental car (Croatia), subways (Vienna, Prague), trains (Croatia, Slovenia, Austria, Czech, Poland), commuter trains (Vienna, Sopot/Gdansk) and a night-train in a sleeper car (Prague to Warsaw).
And lets not forget a lot of walking :-)
It was fun! Didn't expect to do any driving, and the number of ways we got around by some sort of bus always surprises me, especially in Poland, where private buses are everywhere.