Changing the beginning of the picture environment to something such as
\begin{picture}(200,240)(-7,28)% changed last digit to 28
\multiput(0,0)(0,56){5}{% increased from 4 to 5
\multiput(0,0)(95,0){2}{% no change here
looks good on the PDF, but might need tweaking based on your exact card stock.
On the mac I had to use 24 instead of 28 for some reason, to get this image shown below.
Notes:
- You will most likely need to play with some of these parameters to get it to print precisely for the card stock that you have. The only way to do that is try print this out, and see how close it is with you actual card stock, and reiterate.

Code:
\documentclass[11pt]{article}
\usepackage{graphicx}
\usepackage{latexsym}
\usepackage{epstopdf}
\usepackage{color}
\usepackage{fontspec}
%\setmainfont[Mapping=tex-text, BoldFont={BentonSansMedium.otf}]{BentonSansBook.otf}
\pagestyle{empty}
\definecolor{purple}{cmyk}{0.82,1.00,0.00,0.12}
\setlength{\textwidth}{8in}
\setlength{\oddsidemargin}{-1in}
\setlength{\evensidemargin}{-1in}
\setlength{\textheight}{10in}
\setlength{\topmargin}{-1in}
%\newcommand{\clogo}{\includegraphics[scale=0.625]{./Logo.jpg}}
\newcommand{\cname}{\textbf{\textcolor{purple}{My Name}}}
\newcommand{\ctitle}{My Position}
\newcommand{\cemail}{myemail@email.com}
\newcommand{\cadra}{\textbf{Address 1}}
\newcommand{\cadrb}{Address 2}
\newcommand{\cadrc}{City, State, Zip}
\newcommand{\ccontact}{t. 123.456.7890\hspace{4.44 pt}www.website.com}
\begin{document}
\setlength{\unitlength}{1mm}
\begin{picture}(200,240)(-7,28)% changed last digit to 28
\multiput(0,0)(0,56){5}{% increased from 4 to 5
\multiput(0,0)(95,0){2}{% no change here
\begin{picture}(89,51)(0,0)
\put(0,52){\line(0,1){3}}
\put(-1,51){\line(-1,0){3}}
\put(89,52){\line(0,1){3}}
\put(90,51){\line(1,0){3}}
%\put(3,48){\line(1,0){83}}
\put(14.5,27.75){\scriptsize \cname}
\put(14.5,24.5){\scriptsize \ctitle}
\put(14.5,21.25){\scriptsize \cemail}
\put(14.5,14.75){\scriptsize \cadra}
\put(14.5,11.5){\scriptsize \cadrb}
\put(14.5,8.25){\scriptsize \cadrc}
\put(14.5,5){\scriptsize \ccontact}
%\put(4.75,35){\clogo}
%\put(3,3){\line(1,0){83}}
\put(0,-1){\line(0,-1){3}}
\put(-1,0){\line(-1,0){3}}
\put(89,-1){\line(0,-1){3}}
\put(90,0){\line(1,0){3}}
\end{picture}}}
\end{picture}
\end{document}
\multiput(0,0)(0,56){4}{and\multiput(0,0)(95,0){2}{seem to be something of a 4x2 grid. So you could try changing the first4to a5to hopefully get a 5x2. – Peter Grill Oct 06 '12 at 06:53