For future reference here is the final result with pixel perfect precision:
The CSS code:
._25 {
width: 21%;
display:
I think this is what you are looking for:
http://www.alistapart.com/articles/prettyaccessibleforms/
It should help simplify your structure a little bit. It doesn't explicitly describe how to make multiple column forms, but the technique could probably expand to that with some creativity on your part.