If you have any $75+ items on your shopping list, you can save $15 today by buying them through eBay. Just use promo code PREMEMDAY15 at checkout (in conjunction with selecting PayPal as your payment method) to get the discount.
Unfortunately, the code excludes gift cards, money, and, uh, real estate, but otherwise, go nuts. Just note that this deal is only valid until 11PM ET tonight.