Travel Route
(click on map to zoom in)

Scandinavia Russia
UK
Switzerland Eastern Europe
China Western United States Eastern United States
France
Italy Greece
Spain
Spain
North West Africa North East Africa
India China
Western United States Latin America
South East Asia Central America
Northern South America
Southern Africa Northern South America
Central South America
Australia
Southern South America
New Zealand

Distance Traveled = 

Estimated Distance Yet to Travel = 

(To convert kilometers to miles, multiply by 0.621371)

See World Atlas Facts here

This has turned into a bigger trip than I bargained for.  As it turns out I don't think I'll plan out every little detail, complete with departure days, arrival days, and all that jazz.  Instead, I'll have a rough idea as to where I'm going for the next month, how I'll get there, where I'll stay, and what I'll do.  Beyond that month-by-month basis, all I know is where I hope to go next as outlined in the map above.  This has its pros and cons:

Cons

Pros
-Hard to find cheap tickets last minute

-Can't just "walk into" all countries without a visa

-Some countries require an exit ticket, and/or proof of accommodations, and/or specific immunizations just to get in
-Primarily freedom (I can go where the wind blows me)

-I can decide I've fallen in love with county X, and don't want to leave

-I might find out about a much cheaper place to stay, or means of over-land travel that I would never have found online, or in a book at home

-I might find out a place I planned on visiting should not be seen, or vise versa: a country I never planned on visiting is a must-see

-Political demonstrations, or closed borders won't ruin the rest of my trip

-I can depart pretty much anytime without much pre-planning

To minimize problems, I am well aware of visa, immunization, and entry requirements of the countries I anticipate visiting.  I have all the immunizations needed for most of the world, and know how to get visas to countries while I'm abroad.  As for airfare, I hope to minimize air travel by going overland when possible.  I'm not claiming this will prepare me, but I am at least aware of future hurdles.

I would say that as long as you have the cojones (and expect some major speed bumps), traveling month-by-month is more exciting and adventurous.  That said, all I can say about the length of the trip is that it will probably take more than 12 months.