image hosting question...if answered, hot chick pic to come...

I have a great pic of a girl I know at a halloween party. tiny baseball uniform w/ skirt, her hot friend wearing a tiny cop outfit....man. I went to imageshack and chose it as a pic from my desktop. Which size to I make it, and which link do I choose to get it here? It will be worth the trouble, believe you me. And if it makes a difference, I have a mac.