There are online programs that can be completed from anywhere in the world; and the FAST Train program at George Mason University is specifically designed for trailing partners.
I found another possible alternative in the NY Times, which may be a good choice for those that expect to do tours in Washington D.C., as well as abroad:
"...Career Switchers program, the Virginia-based program that requires applicants to pass an Educational Testing Service exam in the subject matter they want to teach, take an online course and attend a series of meetings to learn classroom teaching skills.More from the NY Times at http://www.nytimes.com/2009/10/15/your-money/15TEACH.html?em
The program, which has helped more than 500 people earn licenses, costs $3,150 and takes about 18 months to complete.
Virginia has one of the most streamlined programs for career changers and is among the 47 states that accept alternative teacher training. Over all, about 600 such programs contribute about 20 percent of the country’s new teachers each year, according to the Education Department.
Like the Career Switchers program in Virginia, the American Board for Certification of Teacher Excellence offers an online program that costs $975 and has so far issued 1,900 certifications. They are accepted by nine states, including Florida, Missouri and Pennsylvania. The board says people 50 and older account for one-fifth of its participants."