Nielsen Home Scanner has returned and has opened up positions on their panel. If you have not signed up before I would suggest you do so now.
How it works is they send you a scanner and all you do is scan the products that you buy. This could be your groceries or even personal items. Then once a week you will send them a list of everything you have bought over the course of the week. Each week you transmit your scans, you will be awarded points.
Once you build up enough points you can trade these for gift cards, electronics and even laptop computers!