Facebook have unveiled a new feature for smartphone users (which is the majority of their users) that allows Facebook to recognise what you're watching or listening - in a very similar way to Shazam. The feature uses the microphone to automatically detect the audio, this is then matched to millions of songs and TV shows from around 160 channels. The new feature must be turned on by Facebook users and once it is on will work automatically with the recognised music or TV show showing in your post (if you want it to).
This is currently being rolled out to US users and is expected to be a slow roll-out to other countries.