Not a pain at all, in fact I was wanting to get around to this eventually. While this isn't as elegant as I want it to be, this should do it for you. Basically it adds the Group Membership and a blank area below the current profile. You can swap the Group Membership and Extra Info areas if you'd like, just have to swap the code in the appropriate areas.
REPLACE:
Code:
</tr>
</table>
$footer
</body>
</html>
With:
Code:
</tr>
<tr>
<td class="tcat" width="50%">$vbphrase[group_memberships]</td>
<td class="tcat" width="50%"> <em>$vbphrase[n_a]</em></td>
</tr>
<tr valign="top">
<td class="panelsurround" align="center">
<div class="panel">
<div align="$stylevar[left]">
<div class="fieldset">
<if condition="$show['extrainfo']">
<table cellpadding="0" cellspacing="$stylevar[formspacer]" border="0">
<if condition="$userinfo['birthday']">
<tr>
<td>
<strong>$vbphrase[birthday]</strong>:<br />
$userinfo[birthday]
</td>
</tr>
</if>
$customfields
</table>
<else />
<em>$vbphrase[n_a]</em>
</if>
</div>
</div>
</div>
</td>
<td class="panelsurround" align="center">
<div class="panel">
<div align="$stylevar[left]">
<div class="fieldset">
<table cellpadding="0" cellspacing="$stylevar[formspacer]px" border="0">
<tr>
</tr>
</table>
</div>
</div>
</div>
</td>
</tr>
</table>
$footer
</body>
</html>