Admin plug-ins

http://rudd-o.com/projects/wp-admin-themer/

http://codex.wordpress.org/Creating_Admin_Themes

http://wordpress.org/extend/plugins/adminimize/

http://wordpress.org/extend/plugins/easy-admin-color-schemes/

Git GUI

Overview of GIT GUI clients:
http://theappleblog.com/2009/03/10/using-git-with-os-x-6-tools-to-get-you-up-and-running/