First go through Shop at Home to go get 25% cash back on your purchase. After selecting the gift certificates you want, use code DINE to drop the price 80%.
I just bought a $100 gift certificate to a nice restaurant and the final cost was just $6!
*If you have never used certificates from Restaurant.com. be sure to read the fine print. While you can definitely get some great dining deals, there are restrictions. Most have a minimum purchase requirement, exclude alcohol, and add gratuity automatically. Just read before you buy!