How can you afford to travel for such a long time?

Well, we saved...saved...and saved some more.  We're not trust fund babies, there's no inheritance, and we didn't win the lottery.  We both had good jobs and once we decided to focus on travel, we found it easy to live a frugal lifestyle.  It's also helpful we didn't have kids or dependents at the time.

We decided that we could completely live off of Brenton's salary as a firefighter while we were preparing for our trip.  There were sacrifices to make this work, but it meant that all of Shannon's salary as a nurse would go into the travel fund.  Anytime unexpected money came in, we immediately put it in the trip fund and forgot it was there.

We had a friend move in to split the rent and utilities.  We avoided expensive bar tabs and eating out as much as possible.  We tried to keep up our social life by inviting friends over for drinks or potluck dinners.  We haven't had cable TV in years, but that's usually first to go when budgeting for this lifestyle.  Shannon picked up a second job and Brenton did odd jobs on the side and worked lots of overtime, even bartering services by building websites for people during his free time.  We stopped going on unnecessary trips.  This was pretty difficult with our families living on opposite corners of the country, but no one said sacrifice would be easy!

We had to look at every potential purchase in a different way.  Of course there's the NEED vs. WANT dilemma, but we also asked ourselves "will we use this on our trip?" or  "what could I use this money for in South America?".  Usually these questions give us the strength to put down that tempting Justin Beiber poster without spending a dime...there will be plenty of time for regretful purchases after the trip.

Luckily we had no debts aside from Shannon's student loans.  We could not get them deferred so our options were to pay them off completely or simply continue payments.  We ended up using some of Brenton's 457 funds to make the payments on Shannon's student loans while we were traveling.  
 I know financial advisors wouldn't approve of this, but we're not waiting until retirement to live our lives. As Brenton always points out, in his line of work he'll be lucky enough to reach his retirement age and still have his health.  So we might as well enjoy our health while we have it.