I've worked on a few different continents since 1996, both in short and long engagements... there are three ways to do this:
- Join a huge consulting firm that will send you places. This is a huge hassle as they will not even send you where you want to go, and when you get there, you will do nothing but work. I know this from friends who have had such jobs.
- You become a God and travel around the world as an independent consultant. For this, any niche is good, because you'll be the point man in some really complex space in which only you are known to solve the problem.
- I could never become a God (for lack of interest, talent, luck, or whatever) so I tried to become as standard as possible (for example, I fit 90% of the J2EE developer profiles when I got to Spain). This worked pretty well.
That being said, it's not exactly true. I started working in Spain because I also had teaching experience and eventually did corporate training in J2EE... so what's the point? Keep yourself general and in popular technologies so people can hire you. But, at the same time, work in areas that you like, because you will also get hired for your particularities.
If you like travel, why would you want to work remotely? So much of travelling is working with the local freaks (no offense to the freaks of any nation out there).
Only now am I able to work from anywhere with remote clients. I don't know of any tricks to get those jobs, and luck and loving what you do help.