(NB: this does NOT count airports. In my book, you have to set two feet on the actual soil of the place (ie no driving through!)
Also, this map would be rather impressively filled up if you only went to seven countries: Australia, Russia, China, India, Brazil, US and Canada. Don't waste your time on piddly countries like Israel and Japan like I did (note small red speck in the Middle East region)!
To create your own map, go here.