All this advice is so depressing! Don't smile, grit your teeth, etc.
But thanks for the advice about growing out my hair and such.
As for pictures... heck, I was happy to be with my buddies at new years! I think it would look rather silly if I'd been gritting my teeth while my friends were grinning next to me

Yearbook isn't a problem - I'm in college and we do have a "magazine" that we put out at the end of the year, but it's not hardbound or anything like that, and we pick whatever picture we want in it, so I can just take picture after picture until I have one I like.
But yeah, I'm thinking about new glasses.