I just booked our shuttle ride to the airport for our honeymoon.
Delaware Express ( www.delexpress.com ) has a promotion right now using the code "EXPRESS" for 25% off your shuttle service. This promo is only available by booking online at their website. I don't know how long the code is good for.
If you'd like to use it, click on "Shuttle Reservation" and at the bottom of the screen there's a box for "Frequent User Login". Enter the code in that box.
We needed a shuttle because our flight leaves at 7am the morning after the wedding. We didn't want to make any of our family/friends drive us that early. The promo saved us about $15!