Staples back to school promotions include several items for Free this week. In my area there are discounts on laptops, monitors, graphing calculators, USB flash drives and scientific calculators. I'm not sure how much the offers vary from store to store.
Here is the Staples back to school ad for my local store: Staples Back to School. Since I'm pretty sure you don't live close to my store be sure to enter your own location to get the relevant ad.