I regrettably always have coupons that expire before I can use them. I good way to put them to use is to send them to our Military families stationed overseas. They can use our expired coupons on our military bases for up to 6 months AFTER they expire! They can only accept "regular" coupons like direct from the manufacturer and newspaper coupons (no internet or instore special coupons accepted).
Here is a link to another great site. Jen keeps a running list of oversea military bases that accept expired coupons. Check back frequently for updates.