I watched an interview with her once where she explained why she calls herself Miley Cyrus now instead of her given name, Destiny Hope Cyrus. Apparently the story goes that when she was a baby, she was incredibly smiley (which hasn't changed!), so Billy Ray (her father) nicknamed her smiley. Now I believe, if I remember correctly, that when she was quite young and in either kindergarten or early elementary school, she used to write her name on her homework as Smiley, but without the S. After that, the name just sort of stuck, and thus today she calls herself and is called MILEY!!