The original race I was entered to do was the Rock and Ice Diamond Ultra. This however was cancelled and I managed to find something even tougher!
In March 2010 Nik Cook will be taking part in the 6633 Ultra

 www.6633ultra.com. 6633 is the latitude of the Arctic Circle that he’ll cross 26 miles into the race. 

He’ll have 72 hours to cover 120 miles throughout which he will be battling against temperatures as low as –40C,90 mph+ winds, mountain passes and having to drag all his food and equipment behind him in a sledge.