Take 10% off at best-of-breed online jeweler Blue Nile through 3pm EST 8/19 when you enter JEWELRY39 in the "reference code" box. Blue Nile is the largest online jeweler, having sold over 150,000 engagement rings. They buy diamonds through the same wholesalers that Tiffany's does, but can sell for 20-40% less. They have a well-explained website (see their wedding ring guide, for example), guiding men (mainly, including myself) to an informed purchase without the sleazy salesman. FedEx Priority Shipping is free on all orders, there's no sales tax and a fully guaranteed 30-day return policy. The 10% will apply to settings but not diamonds with "build-your-own" jewelry because prices are already so low.