ballot paper design

As a part of my research for LazyGov and associated projects I am interested in the design of ballot papers and the mechanisms of voting / selecting. Basically I want to find some resources of the designs that have been tried out there in the world, both paper and digital interfaces.

They do not have to be for governmental elections, any kind of voting process.

So if you know of any online resources describing the design of various ballot papers from around the world then please let me know in the comments.