Transposer

The Transposer ingests single items into tubes, and can also serve as a valve.

A Transposer is capable of:
 * Ingesting items thrown or dropped into it, or pushed into it by a stream of water, without needing a redstone signal.
 * Sucking all items in front of itself in a two-meter distance upon receiving a redstone pulse. A vertically-oriented transposer embedded flush in a floor will ingest items sitting on all the eight neighboring blocks on the floor.
 * Sucking one item from a container (chest, for example) upon receiving a redstone pulse.
 * Sucking everything that arrives via tube when connected to tubes in-line, thus being a valid receiver.
 * Shutting off when receiving a continuous redstone signal, acting as a closed valve if connected in-line.

What happens when a Transposer's output tube is not connected to a valid receiver? If the Transposer is connected in-line it will backstuff everything arriving in the input tube, otherwise it will drop items back on the ground.