It has to be a fully functional and operating aircraft first off. Given that, what are some of the more unusual uses for an aircraft?
I found this one. It is an An-2 operated by a catholic association in Hungary, and it is used to perform aerial weddings.
I can see the service now:
Groom: I Jack, take you Jill, to be my wedded wife. To have and to hold, from this day forward, for better, for worse, for richer, for poorer, in sickness or in health, to love and to cherish 'till death do us part or the aircraft falls apart.