http://sta2i.fr/a-propos/nos-garanties Two column for LaTeX from Pandoc.
http://kilim.fr/?karnavalydwona=femmes-qui-cherche-l\\\\\'amour Add twocolumn and replace longtable with supertabular.
\documentclass[twocolumn]{article} ... \usepackage{supertabular} ... \begin{supertabular}[c]{@{}lll@{}} ... \end{supertabular}
To make a figure span over two columns, use figure*.
\begin{figure*}[htbp] ... \end{figure*}