In case you missed it last night on American Idol, after the Top 24 Semi Finalists were announced, the greatest thing that has ever happened on American Idol happened- and it wasn't planned.  Aerosmith front man and American Idol judge Steven Tyler decided he wanted to go for a swim.  Watch it now! Randy and Jennifer do most of the talking on American Idol, but Steven Tyler is certainly the showman as evidenced by his stripping down and impromptu jump into the pool.