As an UK based employee or a UK company that now has a VERY large US owner, I am interested in this thread. I think in the wake of Enron, Sarbanes-Oxley etc etc, there is a real interest in your side of the pond in making sure IT departments are running to industry recognized 'best practices'.
ITIL, of those I've seen is largely becoming the most prevalent of these. It really wins in that it is not a hidebound set of rules, but a set of guidelines, which are specifically designed to be tailored to your organization. Ie: here is the best practice - this is where you should be aiming to be, if you do something else ensure it is aiming to reach this standard. Our US parent has a 30 man, 30 million dollar budget working on rolling this out across its vast US enterprise.