The problem of whether or not a smooth closed manifold admits a Riemannian metric whose scalar curvature is everywhere positive (PSC-metric) is an old one and a great deal is known about it. More recently, attention has shifted to the problem of understanding the topology of the space of such metrics and many interesting results have been forthcoming. In this talk we will discuss some analogues of this problem for manifolds with boundary and also manifolds with Bass-Sullivan singularities. We will look at some new results arising from joint work with Boris Botvinnik.