We describe a proposed new class of optonanomechanical integrated photonic devices that can have self-adaptive behavior and self-adaptive optical frequency response, through the use of optical forces to manipulate their movable parts. We propose applications for this technology, and show how such devices can address the enormous dimensional and thermal sensitivity present in nanophotonic structures. Through synthesis of the optomechanical potential, we propose to design and control either the effective optical, or the mechanical, properties of the nanostructure, such as a giant effective optical nonlinear response, nonlinear dynamics and memory. We show device designs that can trap desired states at picometer resolution. We also describe the design of a novel, self-tuning microcavity design whose moving parts adjust in response to light forces alone to always place the resonance at the wavelength of the incident light over a wide wavelength range. This device concept provides an athermal resonator design (temperature-independent resonance frequency), without use of materials with negative thermooptic coefficients. It could also address a major challenge with conventional strong-confinement (high-index-contrast) integrated photonics - their extreme sensitivities - through a self-locking filter bank and optical cross-connect proposal, that in principle can use arbitrarily low power to trim resonant filter passbands to a wavelength channel grid.