Materials in which electron interactions fundamentally change the physical state may offer the possibility for new electronic devices unattainable any other way. Current examples of physical effects include the ultra-fast metal insulator transitions in VO2 and high temperature superconductivity in the cuprates and iron-based materials. Both of these cases cannot be described without accounting for both electron correlations and quantum mechanics. I will talk about our efforts to use high performance computing to directly simulate many-body quantum problems for these materials. This talk will be aimed at non-specialists and will include a discussion of the challenges inherent in the problem as well as those that we have faced while developing the community quantum Monte Carlo code QWalk.