Sort of a side note, but anyone applying to law school (especially in this competitive environment) should drop the word "optional" from his/her vocabulary. If a school invites you to submit something if you choose to do so, do so unless there is nothing useful you could submit in response to that invitation. While a school may not require letters of recommendation, many (read: most) of your competitors will be submitting them. In addition to the fact that they will then have positive material in their files that you don't have, they'll look like they went the extra mile while you will look like you did the bare minimum required.