I helped write and CD the first Citi Olympics project "Every Step of the Way."
It was about 6 months of hell, but I'm proud of the results.
We created the usual suspects: TV / outdoor / banners / content films.
But the unique thread through it all - a charity program.
Every time you interacted with your chosen athletes either on our site, or on twitter, or on our custom-built "Cheer" app--your action was given a value. This value was donated by Citi to the athlete's charity.
Obligatory Case Study video below. :)