Here's the plan;
Team 1 races along the Union Canal:- Edinburgh Quay - Falkirk wheel (50.7 Kilometres)
Team 2 races along the Forth and Clyde Canal:- Bowling - Falkirk wheel (56 Kilometres)
Each team has to race in relay transporting a Prince and Princess of Wales sash along their route, teams can change runners whenever and as often as they like. (First team back are the supreme rulers for eternity, second team back are smelly poop pants.)
We should try and get around 10 runners in each team this would average 5K per runner. Most reasonably fit people can run 5K in around 25minutes. Estimated time for the challenge would be around 4 and 1/2 hours.
Each team would need a couple of backup cars to transport runners, perhaps a cyclist to go back and forward checking on runners.
The Prince and Princess of Wales Hospice
http://www.ppwh.org.uk/index.cfm
The Union Canal
http://en.wikipedia.org/wiki/Union_Canal_(Scotland
The Forth And Clyde Canal
http://en.wikipedia.org/wiki/Forth_and_clyde_canal