This person made the simplist turner. Very easy to build.
http://www.backyardchickens.com/a/camilles-homade-incubator
I am building this one that will turn eggs automatically. It can be fashioned to work by hand very similar to the one above. This schoolteacher describes/videos the entire building process perfectly.
http://www.youtube.com/watch?v=DLxT4rutgvE
Just imagine a rod sticking out of the side, attache to the frame that is pushing the eggs. You just PULL the rod over one way about 3 1/2-inches. Six hours later PUSH it back the other way.
I often visit the operation of two brothers locally. They hatch everything from emu eggs to finches. Their success rate is phenomenal. They hatch everything with the eggs laid on their sides. This article and many others here believe likewise.
http://www.backyardchickens.com/a/how-to-incubate-hatch-eggs-just-21-days-from-egg-to-chicken
If I had an incubator with the turner that held the eggs upright (vertical), I would use it. But, I'm building it so....