hey guys, i just received my first macbook pro yesterday. i got a small 13.3" pro with i7. I'm relatively new to apple. i got an iPad 2 for christmas this year and have since switched to an iPhone 4s, iPod touch 4g and now this macbook pro. apple got me . i do have one question. its all very new to me and i can't figure out how to change my log in picture.you know when you first boot up and have to punch in your password.., id like to put a little apple logo pic there. appreciate any help.