I've been writing in LaTeX a lot recently, and found a nice little package to use when composing a document with authors with different affiliations. Often, author order is affiliation independent, so the authblk package makes all this possible. Here's the sample code:
\documentclass[10pt]{article}
\usepackage{authblk}
\renewcommand\Affilfont{\itshape\small}
\begin{document}
\title{Author Affiliations in \LaTeX}
\author[,1]{Arthur A. Filliation\footnote{aaf@mail.com}}
\author[,2]{Arthur A. Filliation Jr.\footnote{aaf2@mail.com}}
\author[1]{Con T. Ributor}
\affil[1]{Department of Latex Studies.}
\affil[2]{Typesetters of America}
\date{\today}
\maketitle
\end{document}
A few notes. First, renewing the command \Affilfont allows you to change the look of the affiliation list. However, the small italic font seems pretty standard, so this is what I've always used. Second, the option following the \author command adds a superscript corresponding to one of the affiliations stated by the \affil command. When using this command while also adding a footnote for contact information, the two superscripts will need to be separated by a comma. You'll have to manually put this comma in after the \author command. When all is said and done, you should get this: