Not only do we use coupons, we push the limits. On more occasions than I can count I've asked a vendor to make an exception. Usually it is to substitute for another item on a buy-one-get-one-free deal. My husband is a vegetarian, and most of the coupons we find are for meat-based meals. The vendor is usually happy to substitute because veggie options are less expensive. We've also had luck with restaurants taking a coupon at lunch even though it says "for dinner" only.
A key to making this work, ask BEFORE you settle in. In this economy a potential customer is a customer the manage wants to please. They want you to take a seat, and a usually happy to be flexible with a coupon. But, be prepared to walk.
Any great coupon stories out there that you want to share?