Some of my friends at my work are taking part in this: http://www.gamingforothers.com/ From 11am tomorrow, they will be playing though Mario games like crazy. Feel free to watch the feed, and if you want them to keep going, donate! Personally I think there is going to be some pitfall-induced rage live on the internet.
They are now on £950 and are into their 36th hour of constant mario. Please at least watch to support them and spread the word. So close to the grand mark!