Thanks for the comments on my goal. I'll be starting a web site that chronicles the journey beginning in February, and when I do that I'll make a post about it somewhere in the appropriate FT forum.

As for the calculations, I've already been to 72 countries, so my goal is focused on all the places I haven't been yet. I lived in West Africa for four years, so I'm used to challenging travel situations, and I have a lot of countries in Africa off the list already. But yes, I realize that the goal will still be very challenging.

The list I'm working on is 203 countries-- the 192 U.N. members that paul4471 mentioned, plus a few places that aren't technically countries in a political sense but really should be-- Kosovo, Taiwan, Western Sahara, Somaliland, etc.

As KiwiFlyer correctly noted, the greatest challenge is that as you visit all the "easy" countries, the hard ones get harder and you end up going back to a lot of hub cities to try to get to new places. I still haven't done much in the South Pacific or in Central Asia.

Anyway, more details on my project are coming soon. I appreciate having a community here that appreciates a goal like this.