If you want...when i took it like 07/08..i DID NOT lol...because incase i didnt do so well, i didnt want my application to be tossed in some of the schools i applied to.
Im glad i didnt, i took it in the beginning of my junior year...and when i took it again beginning of my senior year i probably went up 150+ points.
If i were you right now, i probably wouldnt...i believe after 08...you can choose to send whatever SAT scores you want now (my year colleges saw all attempts) so if you dont think you will do well, wait, do well then send the one you want them to see.