OK, stop sniggering at the back. SNOT is a lego acronym, and it stands for Studs Not On Top. Quite often you need a shape that can only be found by building with the studs facing forwards, sideways, or even upside down. Here are a few ways to do this.
Flower power – two 1xn bricks can be held together with lego flowers, and the result is a brick with studs facing 180 degrees from each other.
More 180-degree SNOT, here using several of The One Ring from the Lord of the Rings range. Here the studs point together and the bricks are offset upwards by the thickness of one plate.
A slightly more complicated way to achieve 180-degree SNOT, but the join is exactly two bricks in height.
Two headlight bricks and a 1×1 tile combine to produce a piece the same size and shape as a regular 1×2 brick, but with a stud on top and bottom (and on one end).