Compact Admin is a WordPress plugin that makes the posts and pages lists in the admin pages more compact. Instead of taking up two lines of text, plus excessive margins, only one line is used per post/page. It also replaces the cluttery en dashes with whitespace.
Compact Admin is released as open source and can be used, modified and redistributed in any way possible.
Plugin homepage: http://lumens.se/compact-admin/
Download: http://wordpress.org/extend/plugins/compact-admin/