Go to
http://www.gaminglagoon.com/?ref=20464 and make an account. After you make an account fill out their free surveys. Just bullshit the surveys untill you do the specified amount of pages and then go to the offers page and click completed, 15-20 minutes later you will have however many points the offer was worth. You need 20 points for the 1600 microsoft points. There are also other things like Wii points and a Wireless 360 headset. If you have any questions either ask here or message me on xbox live.
EDIT: I just noticed that someone else already posted this, my bad I don't get around to much on here anymore.