Steve Martin sends the following:
Tim and I have just completed the Marathon Des Sables. At 250km it was the
longest ever and with temperatures of 40+ C it was as tough as they say. The
stages were 29, 35.5, 40, 82.2, 42.2 and 21.1km long. We carried all our food
and equipment, just water and an open shelter (tent?) were supplied. It was a
real eye opener to see collaspes runners on saline drips part way through the
race and a real challange not to become one of them.

An amazing achievement, I hope much more information will follow.