There's a new Web site in town that has Cheapskate written all over it: Free Shipping On. Terrible name, great service: It enables you to search Amazon and eBay for only those items that have free shipping. It also corrals free-shipping deals from over 500 other stores, from Apple to Home Depot to WebUndies.com.
I particularly like the eBay search tool, as it drives me nuts when I find a seemingly great deal on something and then discover a ridiculously inflated shipping charge. Both the Amazon and eBay tools can be added to your browser's list of search engines, meaning you can use them without having to visit Free Shipping On proper.
While you're at it, stop by Deal Locker, a discount-coupon site from the same developers.