We use digital video microscopy to investigate melting of colloidal crystals under strong 2-dimensional (2D) confinement and frustrated colloidal ‘anti-ferromagnets' in weak 2D confinement. Our samples are composed of NIPA (N-isopropyl acrylamide) microgel spheres whose diameter can be temperature-tuned, and whose pair potentials were measured to be short-ranged and repulsive. The melting experiments revealed two first-order-like transitions from crystal to hexatic phase and hexatic to liquid phase as a function of temperature-tunable volume fraction. The divergences of translational and orientational susceptibilities were used to determine the phase transition points. This approach avoids ambiguities inherent in other analyses and resolved a novel premelting stage in the crystal that traditional analyses incorrectly associate with the hexatic phase. We will also show how these novel microgel spheres can be made to mimic the behavior of frustrated anti-ferromagnets. In this case, we measured statistics of frustrated bonds and collective fluctuations of the degenerate system in space and time. This work was carried out in collaboration with Ahmed Alsayed, Na Young Ha and Arjun Yodh with support from the NSF (MRSEC DMR-0520020 and DMR-0505048). I also thank Tom Lubensky and Yair Shokef for helpful discussions.