The key to this whole lifestyle is setting up your work situation so you can do it remotely. Without this, you're toast. You might be thinking, "Why can't I just work until I save enough money for the trip?" If this is what you are truly passionate about, then working and trying to scrimp and save without traveling in the mean time will be miserable for you. Do yourself a favor and don't postpone happiness now for a short-term payoff later. Get a remote job and you'll be able to keep up this lifestyle for as long as you want.
The easiest way of going about this is to transition your current job into being remote. Obviously, this only works if your job can be done through a computer. More and more managers are seeing the benefits of allowing their employees to work remotely, but some still need a bit of convincing.
Here is the step-by-step process I took to turn my formally-non-remote-job into a means of funding endless world travel.
Step 1: Begin with a gig that can be done remotely. Though most employers require their workers to come into an office, a staggering number of those jobs can really be done from anywhere. In fact, in my personal experience (and I'm assuming for many others as well), I'm much more productive working from home than I am at the office where I get roped into small talk conversations with co-workers. Marketing, computer programming, graphic design, and data entry are just a few types of jobs that come to mind that could be done from anywhere. Avoid getting shuffled in to a job at a large corporation where you're expected to climb the corporate ladder - chances are you'll have no opportunity to take the job remote until you reach the top many years later. Small to midsize companies are ideal, with freelance work giving you the most freedom.
Step 2: Be upfront about your intentions. When I applied to my current job right after my college graduation, we had already made our travel plans for a few months in the future. After my interview I told them about our plans and said that at that point I would either love to do this job remotely or I would find something else I could do. My boss did not sound optimistic about the option, citing experiences he had with past remote employees that didn't work out. Still, the fact that he didn't display downright outrage at the thought told me there was a chance. So, I took the job.
Step 3: Turn yourself into an asset that the company can't afford to lose. During the four months leading up the my departure I embedded myself into every minuscule part of the operation I could. I asked my coworkers to train me on literally everything so that my boss couldn't imagine things running smoothly without me.
Step 4: Take any opportunity you can to work from home. This is one I took out of the 4 Hour Work Week and I think it helped a lot. I stayed home one day when I was sick, but told my boss I'd be working from home. I used that day, and a couple of other weekends, as opportunities to really display how productive I could be out of the office.
Step 5: Have the talk. Don't be pushy, but make sure your boss understands that there really isn't any reason to not let you permanently work remotely. I made sure to mention that I would be just as productive (cite the days you spent working from home, if you have to) and that I'll keep a structured schedule so he always knows when we can communicate. It also helped to clarify that, rather than be constantly on the move and traveling to a new city every couple of days, we'll be getting a WiFi-enabled apartment and staying put for weeks at a time.
As I previously said, getting at least a half-decent job to do while traveling is crucial. If your current job can't be done remotely, however, or your boss won't allow it, there's still hope. Check out "Work From Wherever" part 2 on finding a new remote job.