Powered Hopper Allows Unstackable Items [Edit: False Alarm]

Place down a chest. Throw a hopper next to it, feeding into the chest. Place another hopper on top of that, not facing down. Power the bottom hopper. Put stackable blocks into the top chest; they should not flow, but when you put an unstackable item along, it bypasses the powered hopper and into the chest.

Edit: False Alarm!