Wild Will, I could be wrong (and often am) but there is a second Ironman in the UK. It's at Aberfeldy in Scotland. The cycle is a bit of a slog as it is up and down hills.
You can read a report on it from one of the Tri clubs that took part at:
http://www.ayrodynamic.co.uk/news.htm
I may give Aberfedly a go next year as I fancy a shot at a Half Ironman as a build up to the Full distance sometime in 2005.