This is something that has been getting on my nerves for a while, since I couldn't find any good way to do this. Let's say I have something whose output connection is plugged into the input port of my soundcard, such as an old vinyl player, a radio, a minidisc player, whatever. What I want is to be able to listen to what the device outputs directly on my computer (in this case, a laptop, so no external speakers cheating).

Additional points if I can also record while I'm listening.