\documentclass[a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage{fullpage}
\usepackage{pstricks}
\usepackage{pst-barcode}
\usepackage{graphicx}

\title{User Barcodes}
\date{}
\begin{document}
%

\maketitle
\setlength\tabcolsep{40pt}


%
\begin{tabular}{ccc}
\includegraphics[width=0.20\textwidth]{userimages/alfkjempestor}
& 
\includegraphics[width=0.20\textwidth]{userimages/tirilane}
\\
\begin{pspicture}(3,1.0in) 
\psbarcode[scalex=0.8,scaley=0.8]{NTNU457343}{includetext guardwhitespace}{code39}
\end{pspicture} 
&
\begin{pspicture}(3,1.0in) 
\psbarcode[scalex=0.8,scaley=0.8]{NTNU318657}{includetext guardwhitespace}{code39}
\end{pspicture} 
\\
\includegraphics[width=0.20\textwidth]{userimages/oysteini}
&
\includegraphics[width=0.20\textwidth]{userimages/almelid}
\\
\begin{pspicture}(3,1.0in) 
\psbarcode[scalex=0.8,scaley=0.8]{NTNU458221}{includetext guardwhitespace}{code39}
\end{pspicture} 
&
\begin{pspicture}(3,1.0in) 
\psbarcode[scalex=0.8,scaley=0.8]{ALMELID}{includetext guardwhitespace}{code39}
\end{pspicture} 
\\
\end{tabular}
%
\end{document}