(http://www.stadt.no/kontakt.html )
The page is a table-based layout. Adding an extra column could be as simple as changing this (notice my suggested change in bold) -
e-post: <a href="mailto:thomas@stadt.no">thomas@stadt.no</a><br>
</p>
</div></td>
<td valign="top"><div align="center">
to this -
e-post: <a href="mailto:thomas@stadt.no">thomas@stadt.no</a><br>
</p>
</div></td>
<td> </td>
<td valign="top"><div align="center">
Then adjusting your cell widths and alignments to suit. Fill in the extra column with the desired content.