This code will simply block all links in your posts to guests, and replaces them with some text. I know Agent Moose made this code too (on my request =D), but somehow its not working, so I made my own. This one is much simpler btw =D.
Here, I made a preview (this one is fake, it's just to get the look of it):
[Only registered users can see links. Please Login or Register]There is also a preview if you log-out

Thats with this link:
www.alink.comThere are two versions, one where the whole sentance is a link, and another where there are two words (login and Register.
Text Version:Put this in your footers:
<script>
<!-- Guest Links Blocker -->
<!-- This script is made by Qub1. Find more scripts like this at
http://qub1.smfforfree.com/ -->
if ($("td.windowbg2 span.middletext b").html() != null) {
$("div.post a").replaceWith('
<font color="red">[Only registered users can see links. Please <a href="/?action=login">Login</a> or <a href="/?action=join">Register</a>]</font>');
}</script>
You can edit the red text as you wish, that will be displayed instead of the link.
Link Version:Put this in your footers:
<script>
<!-- Guest Links Blocker links mod -->
<!-- This script is made by Qub1. Find more scripts like this at
http://qub1.smfforfree.com/ -->
if ($("td.windowbg2 span.middletext b").html() != null) {
$("div.post a").attr("href", "?action=join").html("
<font color='red'>[Only registered users can see links. Please <a href='/?action=login'>Login</a> or <a href='/?action=join'>Register</a>]</font>");
}</script>
You can edit the red text as you wish, this is what will be displayed instead of the link.
Thanks for reading!
~ Qub1