This question was asked just yesterday in the Links 2.0 Customization Forum...use the FIND IN PAGE option in your web browser to search for One Column in the Links 2.0 Customization Forum.
SIGH...please click on the Links 2.0 Customization Forum link in the Forum home page! Or use the forum search engine to find one column categories. Why should I re-post codes that have already been posted in the forums?