The Very Very Very First Appearance of Batman!!

Recently I have been thinking about how this year, 2009, is the 70th Anniversary of one of the greatest comic book characters ever, Batman! The weird thing is that DC Comics ( Warner Bros ) has not been hyping that fact very much. Oh, they have mentioned it a little but there's NO huge fanfare like I would like to see. So, then later I got to wonder what was THE very very first appearance of