Micturn ... the dimensions aren't as important as the fact that it has to be less than 200k.  If you have trouble getting it that small and maintaining the image at somewhere around 600x800 or 768x1024 (ish) try downloading a free program called Irfanview.  Works like a charm! 

Love the baby ducklings, Luis!  Sweet! 

"If your pictures aren't good enough, you're not close enough."  ...  Robert Capa