Aurora Flight Science's prototype VTOL Skate folds up real small (see below). From the official site:

"Aurora’s Skate UAS merges the simplicity and endurance of a fixed wing platform with the maneuverability and mission flexibility of a vertical takeoff and landing (VTOL)
asset. Independently articulating motor
pods allow the Skate UAS to rapidly transition between vertical
and horizontal flight. Transferring from
hovering to wingborne flight increases the endurance and range
of the system to levels characteristic of
a fixed wing platform and far beyond those of a traditional VTOL
asset. The thrust vectoring provided by
the motor pods also enables extreme maneuverability allowing the
Skate UAS to fly both vertically and
horizontally indoors, enabling rapid navigation of cluttered
environments such as city streets or inside
buildings."

(Photos from Wired's Danger Room blog)