audio input on the s4
does any use the audio inputs on your s4 for anything
I’ve seen a few guys using them to play records.
hook a turntable on it to sample records.
an ipod/zune as an emergency plan is always useful and saves the day .. i mean the gig 
When I’m mixing with my buddy, we plug his VCI into channel C, and switch off between each other by bringing his channel up. I then also record the whole mix on the S4 audio recorder.
Also, if I playing out I too would also use the input as an emergency fail-safe with my ipod plugged in.
Some use it for a ipod/mp3 player, incase of software crash.
Use my Inputs for keyboards/synths.