The bucket drop used about 1/4 mile of nylon cord, with a bag tied to the end. By circling at low altitude, wind resistance caused the cord to spiral around in the shape of an inverted cone. The bag could be stabilized over one spot on the ground, low enough for a person to reach up and grasp it, to exchange mail, medicines, or in this case gifts.
It took a great amount of skill and practice. Wind was the main problem. The pilot cannot vary the angle of bank to correct for wind drift...the bucket would be all over the sky! He has to establish a proper and constant bank at exactly the right altitude, then let the wind drift him over the spot. Once a person gets hold of the bucket, it becomes easy to maintain position."
--And I found some Pics of this being done in a Cessna 170.
http://www.dtlinn.com/bucketdrop.html