Pipes are a new block in minecraft, allowing easier transportation of liquids (currently Lava, Water, Methane, and others from mods i.e. Oil).
Created with four iron bars aranged in a diamond shape on the workbench (one at the top, one at the bottom, one on the right, and one on the left) allows you to have 8 pipe pieces.
Pipes will only transport liquids when a pump is placed at the end (where you want the water to be transported), even if the water is flowing onto the pipe enterance. As the different liquids travel through the pipes (as an added feature) they will be shown visually.