I don't really see the point, but okay, it would be easy to do, if you mean by having a it on the individual posts then...
have a buttong like 'Return To Top of Post' or something with the code, <a href="#topofpost9"><img src="???"></a>
then at the top of that post have <a name="#topofpost9"></a>, it will just take it to the top of the post, here is an example btw, just using basic html... Put this into notepad and save it as test.html or something...
code:
<html>
<head>
<title>test</title>
</head>
<body>
<a href="#cheese">cheese</a>|<a href="#bread">bread</a>|<a href="#face">face</a><br>
<p> </p>
<p> </p>
<p> </p>
<p> </p>
<p> </p>
<p> </p>
<a name="#cheese">Cheese</a>
<p> </p>
<p> </p>
<p> </p>
<p> </p>
<p> </p>
<p> </p>
<a name="#face">Face</a>
<p> </p>
<p> </p>
<p> </p><p> </p>
<p> </p>
<p> </p>
<p> </p>
<a name="#face">face</a>
</body>
</html>
or of course you could just have <a href="#top"></a>
.
[edit]
of you could have <a name"#toppost"></a> as the name of the first post and have <a href="#toppost"></a> under each post on that...