I would use it for various reason:
-as an amp for other things (like watching a movie on TV)
-maybe recording things if the line-in goes to the processor instead of to the amp stage.
-with my phone to be able to listen to music and talk on the phone without pluging / unpluging cables:
EDIT: in this drawing, the music is supposed to come from the DAP, not the phone. What comes out of the phone is just the phone conversation sound (that would take over the DAP sound or be mixed with it).
Edited by JediRemi - 7/14/14 at 12:32pm