The Eyjafjallajokull volcano in Iceland is difficult to spell, but is pronounced, "Ed." The way to remember how to spell it is to put your forefinger on the top row of your computer keyboard, count over three keys, then drag your finger to the other end of the row.
All right, none of that is true, but it is true that the volcano blowing its top in Iceland has driven European travel back 70 years to the early days of World War II. That was one of the last times when large numbers of people couldn't get from where they were to where they wanted to go.
There are tens of thousands of people stranded in places they don't want to be. Granted, being stranded in London for a week isn't the same as being stuck in Fallujah or Mazar-i-Sharif, but if you don't want to be there; you are still stuck.
A friend of mine is, indeed, stuck in London. We discussed the notion her getting to Casablanca. Then, if she could get her hands on some Letters of Transit at Rick's Café Americaine, she might make her way back to Portugal and then to the U.S.
For those who may not have been following this, Iceland is, according to the BBC, "a volcanic hot spot on the Mid-Atlantic Ridge - the dividing line between the Eurasian and North American continental plates."
You know how the Hawaiian Islands were formed (and are still being formed) by undersea volcanoes? Well, think of Iceland as Hawaii without the palm trees.
Iceland has 35 active volcanoes. One of them, Eyjafjallajokull, is considered to be a minor player in the Volcanic orchestra of Iceland, but the last time it erupted (December 1821) it lasted for 13 months.
While Eyjafjallajokull isn't doing any real damage in Iceland, it is doing enormous damage everywhere else. That's because every route of flight from just about anywhere in Europe or the Middle East to the U.S. of A. has to go through the ash cloud that - can't we just call it "Ed?" - Volcano Ed is spewing.
I know you've heard this term before: A Great Circle Route. In navigating around the Earth (or any globe), the shortest distance between two points is a great circle, which is defined as "a circle that runs along the surface of a sphere so as to cut it into two equal halves. It is the largest circle that can be drawn on a given sphere."
I found a great circle route calculator (which I have posted on the Secret Decoder Ring Page) which allows you to chart a great circle route between any two airports - London Heathrow (LHR) and New York (JFK) for instance - which will help you visualize the problem.