Minecraft Villager Trading Hall with Torture Dungeon. Highly Efficient Mob Farm (13000 Drops per Hour) Infinity Anvil. MCTUT - ULTIMATE CHICKEN FARM! (1.7.4 READY) Practical Skills: The Simple Efficient Blaze Farm. Minecraft: New Minecart Door. Minecraft Tutorial - 100% Efficient Item Elevator [1.5.1] (Generikb Fix) Minecraft Tutorial - Item Elevator (Droppers) [1.5 Redstone Update] Fuel efficient furnace, stop wasting coal and use analog redstone to control auto smelting.
SethBling's Storage-Minecart System. MCTUT - Cow Farm & Grill (Sheep Too) (1.7.4 READY!) Tutorials/Item Sorter. The hopper is a useful device for controlling/counting/sorting items.
 Day counter This is a very simple machine for counting days. Every time it becomes day, the dispenser is activated and shoots an item into the chest.  Item counter A mechanism that outputs short redstone signal for every item that goes through the dropper.