Geometrical frustration occurs when interacting degrees of freedom do not "fit" into the lattice in which they find themselves. When the degree of misfit is high, new states of matter and novel excitations can emerge. In magnets these states include spin liquid, spin ice, and an isotropic spin dimer solid. I will broaden the concept of geometrical frustration beyond magnetism and show how to explain phenomena such as negative thermal expansion and large dielectric constants in isotropic solids. Finally, I'll show how novel excitations including ultra-soft spin waves and fractionalized quasiparticles such as monopoles arise from geometrical frustration.