Index: lib/redmine/pagination.rb
===================================================================
--- lib/redmine/pagination.rb	(revision 14901)
+++ lib/redmine/pagination.rb	(working copy)
@@ -235,7 +235,7 @@
         if values.any?
           links = values.collect do |n|
             if n == paginator.per_page
-              content_tag('span', n.to_s)
+              content_tag('span', n.to_s, :class => 'selected')
             else
               yield(n, :per_page => n, paginator.page_param => nil)
             end
Index: public/stylesheets/application.css
===================================================================
--- public/stylesheets/application.css	(revision 14901)
+++ public/stylesheets/application.css	(working copy)
@@ -532,6 +532,9 @@
   color: inherit;
   text-decoration: inherit;
 }
+.pagination .per-page span.selected {
+  font-weight: bold;
+}
 
 #search-form fieldset p {margin:0.2em 0;}