I will introduce and motivate the intitial state problem during inflation, and I will discuss some more or less motivated proposals which relate the choice of the inflationary vacuum to the appearance of new string- or Planck-scale physics. Particular attention will be given to our proposal modifying the initial state based on a general (boundary) effective field theory description. I will move on to discuss the generic effect of initial state modifications on the primordial spectrum of inflationary perturbations, and will end with some comments on the (observable?) distinctions between some of the proposals modifying the inflationary vacuum.