I have been told that Paranoid Android is doing things that Little Snitch can't do. So the question is: Is it possible and neccessary to have both installed in the same machine?
It depends on how paranoid you are. :)
Little Snitch monitors connections to the outside world and informs you when unexpected ones occur. Paranoid Android monitors activity locally on your computer where one program activates another using Launch Services and alerts you when unexpected activations occur. Two different things.
I personally feel that Apple's fixes to Launch Services negate the need for Paranoid Android, but there are still people who enjoy the security of having it turned on.
I am just concern about the new worm "Opener" which for now is more a proof of concept than a threat, but it's better to be alert in case... Also it might take a while before Apple release a patch.
So both wouldn't conflict each other on the same machine?
I beleive you can't be too careful, so I use both.
And, no they won't conflict.
Remember "Just because you're paranoid, doesn't mean that nobody's out to get you.