I have got this working on my site using the following code to replace the bbcode_quote template, and copying q.gif to images/misc
Code:
<div style="margin:20px 10px; background: url(images/misc/q.gif) 0 0 no-repeat">
<div style="padding-left:25px">
<div style="padding:0 5px; border:0px solid #ccc; border-left-width:3px">
<if condition="$show['username']"><div>
<phrase 1="$username">$vbphrase[originally_posted_by_x]</phrase>
<if condition="$postid"><a href="showthread.php?$session[sessionurl]p=$postid#post$postid" rel="nofollow"><img class="inlineimg" src="$stylevar[imgdir_button]/viewpost.gif" border="0" alt="$vbphrase[view_post]" /></a></if></if>
<br />
<em>$message</em>
<br />
</div>
</div>
</div>
<br>
I am no coder, I just tinker with stuff until it works so use at your own risk.
I'm sure somebody else will come up with a nicely coded version soon.