I have been kicking around the idea of making a generic tube like device that could clip on to the feet of a quadcopter.  There are many potential uses for this beyond fishing.  Bandages, water, keys, a cell phone, plant seeds, really anything small that can be delivered by a UAV.  After watching several people interact with the clip while the drone is flying, it dawned on me that there is a better way to do this.  I started sketching a very preliminary idea, but I think this is the direction the project will take.  A quick and easy way to attach a payload to a quadcopter, release it, bring it back and send another payload.