Neither my fiance nor I get excited about cake. But we find Pie to be very exciting.
So on our RSVPs, there's a section where guests can write in their favorite pie. Then each table has a different pie on it.
The pie serves as centerpiece and dessert (we're having a rustic, outdoor wedding, where this makes lots of sense), and it helps us with the seating arrangement, too, so that people can mingle a little more and get to know each other.