Here is what I did.
Edit SHOWTHREAD
Find this section:
Code:
<!-- controls above postbits -->
<table cellpadding="0" cellspacing="0" border="0" width="100%" style="margin-bottom:3px">
<tr valign="bottom">
<if condition="$show['largereplybutton']">
<td class="smallfont"><a href="newreply.php?$session[sessionurl]do=newreply&noquote=1&p=$FIRSTPOSTID" rel="nofollow"><if condition="$show['closethread']"><img src="$stylevar[imgdir_button]/reply.gif" alt="$vbphrase[reply]" border="0" /><else /><img src="$stylevar[imgdir_button]/threadclosed.gif" alt="$vbphrase[closed_thread]" border="0" /></if></a></td>
<else />
<td class="smallfont"> </td>
</if>
<if condition="$show['pagenav']"><td align="$stylevar[right]">$pagenav</td></if>
</tr>
</table>
<!-- / controls above postbits -->
Change it to this (The RED text is the addition)
Code:
<!-- controls above postbits -->
<table cellpadding="0" cellspacing="0" border="0" width="100%" style="margin-bottom:3px">
<tr valign="bottom">
<if condition="$show['largereplybutton']">
<td class="smallfont"><a href="newreply.php?$session[sessionurl]do=newreply&noquote=1&p=$FIRSTPOSTID" rel="nofollow"><if condition="$show['closethread']"><img src="$stylevar[imgdir_button]/reply.gif" alt="$vbphrase[reply]" border="0" /><else /><img src="$stylevar[imgdir_button]/threadclosed.gif" alt="$vbphrase[closed_thread]" border="0" /></if></a> <script type="text/javascript" src="http://apis.google.com/js/plusone.js"></script>
<g:plusone></g:plusone></td>
<else />
<td class="smallfont"> </td>
</if>
<if condition="$show['pagenav']"><td align="$stylevar[right]">$pagenav</td></if>
</tr>
</table>
<!-- / controls above postbits -->
That puts the +1 just to the right of Post Reply at the top.