  Pendant drops spontaneously appear on the underside of wet surfaces through
the Rayleigh-Taylor instability. These droplets have no contact line, they are
connected to a thin liquid film with which they exchange liquid and are thus
mobile: any perturbation will set them in motion. Here, using experiments,
numerical simulations, and theory I show that pendant drops sliding under a
slightly tilted wet substrate can pin on topographic defects, despite their
lack of contact line. Instead, this pinning force has a gravito-capillary
origin: liquid has to moves up or down and the interface has to deforms for the
drop the pass the defect. I propose a semi-analytical model for arbitrary
substrate topographies that matches the pinning force observed experimentally
and numerically, without any fitting parameter. I finally demonstrate how to
harness this pinning force to guide pendant drops on complex paths.
