Their application seems easier to fill out than the entry form for the Taipei 101 stairway race.
From the FAQ:
"The Empire of Atlantium is a self-declared primarily non-territorial sovereign entity and proto-world state that asserts immanent, parallel global sovereignty. The purpose of Atlantium is to promote the idea that sovereignty in the modern world need not necessarily be linked to geography, and that all human beings can and should have the right to choose their country of citizenship irrespective of where they were born, or where they live."