See also http://support.apple.com/kb/TS4088?viewlocale=en_US&locale=e...
I printed the article, the GPU kernel panic log and took them to the Genius bar. Apple replaced the mainboard for free, more than 3 years after the purchase.
It took me more than a year of dealing with random crashes and several visits to the genius bar before I found this article.
Though the downside is that you'd miss the excitement described here...