I just released a new paper with my collaborators Bill Munro, Tim Ralph, Peter van Loock and Kae Nemoto, entitled "Practical effects in the preparation of cluster states using weak non-linearities". In this paper we examine a recent protocol for implementing optical quantum computing using weak non-linear interactions. This is in contrast to the standard optical QC approach of using only linear optical elements. We examine various practical effects affecting the implementation of such a scheme in the laboratory. Our results give an indication of what the experimental requirements are and what the expected sources of noise will be.