@Krista: That is so well put, wow, I'm stunned and in total agreement.
I think that being beautiful means being yourself, and accepting that the you today is good enough and worthy enough of every little thing this world has to offer. Being beautiful means having the capacity to forgive, care, and understand everyone, even the people that may not want to do the same towards you. Being beautiful means knowing that there are some things one cannot change, no matter how hard they try, and that's okay. Being beautiful means understanding and accepting, and treating everyone the way you want to be treated.
And lastly, being beautiful is believing that you already are.