Idiom origins

Posted by Purty burdy on April 02, 2005

I NEED TO FIND DIFFERENT IDIOM ORIGINS FOR A SCHOOL PROJECT BUT I CAN'T SEEM TO FIND THEM ANYWHERE. IF ANYONE KNOWS THE ORIGINS OF "TIP OF THE ICEBERG", "BIRDS OF A FEATHER FLOCK TOGETHER", OR "BY THE SKIN OF YOUR TEETH", IWOULD GREATLY APPRECIATE YOUR HELP! THANK YOU