Courage is the key to friendship. In the youtube video Wheels on the Bus Rap, which I star in three friends have a chose whether they should do something stupid where everyone would make fun of them or have fun and don't care what people think. In this video they have the courage to sing and dance like idiots but it was fun and we where good friends after that experience. Sure we got made fun of a lot and tons of people laughed at us but it took courage for us to do it. What one friend wanted to do the other two also had to do cause there friends.
In the short story Of Mice and Men George has the courage to look out for Lennie, stand up for him, take care of him and even kill him. It takes tremendous amounts of courage to do one of those things but to do all of the at once is truly amazing on George's behalf. It's even because of Georges courage to look over Lennie that they keep the American Dream alive. George's courage is what keeps there friendship strong.
http://www.youtube.com/watch?v=8cz1zweX0FE