DNA is a versatile tool for directing the equilibrium self-assembly of nanoscopic and microscopic objects. The interactions between microspheres due to the hybridization of DNA strands grafted to their surface have been measured and can be modeled in detail, using well-known polymer physics and DNA thermodynamics. We use these interactions to generate a large and expandable library of DNA-labeled colloidal building blocks by utilizing colloidal crystal templates and reprogrammable DNA interactions. The symmetry of the clusters is controlled by the symmetry of the crystal template and the location of ‘seed’ particles embedded within them. From close-packed colloidal crystals, we can generate five distinct cluster symmetries: cuboctahedra, triangular orthobicupola, icosahedra, octahedra, and tetrahedra. These clusters in turn possess directional interactions that can be used for hierarchical self-assembly of still more complex ordered structures. The second half of the talk will discuss the physical origin of the unusual rheological properties of many non-equilibrium complex fluids, collectively termed soft-glassy materials (SGMs) which include such diverse examples as soap foams, mayonnaise, toothpaste and living cells. When activated by internal energy sources, SGMs display dynamic shear moduli that have an unusual power-law frequency dependence, super-diffusive particle motion, and large cooperative particle rearrangements, or avalanches, all of whose physical origins are poorly understood. We hypothesized that these SGM phenomena may emerge simply from properties of their high-dimensional energy landscape function. To this end, we study a minimal computational SGM model whose behavior was determined solely by energy minimization: essentially steepest descent on an energy landscape spanning the configuration space. The model is a wet soap foam consisting of compressible spherical bubbles, whose sizes slowly evolve due to ripening. Surprisingly, we find that the steepest-descent configuration space path is a self-similar fractal curve, resembling a river cascading down a tortuous mountain canyon. The unusual SGM phenomena in our model stem directly from these paths' fractal dimension and energy function, suggesting that such physics may emerge generically in non-equilibrium systems having fractal energy landscapes.