Little Snitch - OS X network firewall you can’t live without

I have been a user of Little Snitch since the not so old 1.2 versions in Tiger. Now the guy(s) are updating it for Leopard - and I’m using the public beta for a few days now. Basically if you want to know what your applications are doing / trying to do behind your back - it is essential.

It has a nice network monitor app that shows you what your applications are doing at any given moment. Really useful. Also - as in the previous versions - you can set up a rule (allow a program) to access a server on the internet (or a certain port on different servers or a server + port combination) for one time only access or until the application closes or forever. Quite a choice, should be enough for anyone.

Some screenshots:

configuration dialog 

network activity monitor