MacUpdate’s promo today is Little Snitch 1.2.4, which is available for US$14.95 — 40% off the regular retail price of $24.95. Little Snitch runs in the background and hooks into the operating system kernel while you are logged in. When an application tries to establish a network connection, Little Snitch intercepts the attempt and brings up an alert panel, telling you all the connection details including the name of the application which initiated the connection. You can either allow the connection, deny it or add a permanent rule for similar future-connections.