"Optofluidics" represents the marriage of optics, optoelectronics and nanophotonics with fluidics. Such integration represents a new approach for dynamic manipulation of optical properties at length scales both greater than and smaller than the wavelength of light with applications ranging from reconfigurable photonic circuits to fluidically adaptable optics to high sensitivity bio-detection currently under development. The capabilities in terms of fluidic control, mixing, miniaturization and optical property tuning afforded by micro-, nano-fluidics combined with soft lithography based fabrication provides an ideal platform upon which to build such devices. Here we present our technique for integrating soft lithography based nanofluidics with e-beam lithography defined silicon-on-insulator photonic crystals. We demonstrate nanofluidic addressability of single, sub-wavelength, defects within the planar photonic crystal and the dynamic tuning of the guided mode. In this paper we focus on the fabrication, integration and experimental details of this work.