[becafuel]

I'm using postbit_legacy with the following changes to go back to top :

<if condition="$show['reportlink']"><a href="report.php?$session[sessionurl]p=$post[postid]" rel="nofollow"><img class="inlineimg" src="$stylevar[imgdir_button]/report.gif" alt="$vbphrase[report_bad_post]" border="0" /></a></if>
		$post[iplogged]
		&nbsp;
<br /><table width="100%"><tr><td align="center" class="tcat"><a href="#top" onclick="self.scrollTo(0, 0); return false;"><span style="font-size:10px;">$vbphrase[top]</span></a></td></tr></table>
	</td>
	<if condition="$show['moderated']">

It adds the phrase "Back to top", depending on your language (here "Haut de page" in french), under every user info, thus permitting to go back to top from everywhere in a thread.