This patch allows disabling the edit and preferences link in the config file. It is backwards compatible (so peoples edit and preferences links won't suddenly vanish). To disable edit or prefs respectively, add the following to the config file:
  'edit' => 0,
  'prefs' => 0, 
Patch:
--- /usr/share/perl5/IkiWiki/Render.pm.orig     2008-12-23 16:49:00.000000000 +1300
+++ /usr/share/perl5/IkiWiki/Render.pm  2008-12-23 16:55:40.000000000 +1300
@@ -80,8 +80,10 @@
        my $actions=0;
 
        if (length $config{cgiurl}) {
-               $template->param(editurl => cgiurl(do => "edit", page => $page));
-               $template->param(prefsurl => cgiurl(do => "prefs"));
+               $template->param(editurl => cgiurl(do => "edit", page => $page))
+                       if ! defined $config{edit} || (defined $config{edit} && $config{edit} == 1);
+               $template->param(prefsurl => cgiurl(do => "prefs"))
+                       if ! defined $config{prefs} || (defined $config{prefs} && $config{prefs} == 1);
                $actions++;
        }