I was just looking for this... By using David's answer, I used a span and gave it some padding (height won't work + top margin issue)... Works like a charm;
See fiddle
<ul>
<li><a href="index.php">Home</a></li><span class="divider"></span>
<li><a href="about.php">About Us</a></li><span class="divider"></span>
<li><a href="#">Events</a></li><span class="divider"></span>
<li><a href="#">Forum</a></li><span class="divider"></span>
<li><a href="#">Contact</a></li>
</ul>
.divider {
border-left: 1px solid #8e1537;
padding: 29px 0 24px 0;
}