Our current paradigm has planets forming within circumstellar disks by the accumulation of micron-sized solid dust grains into planetesimals, followed by the accretion of planetesimals into planets. The leftovers of planet formation are so-called debris disks, the remnant planetesimals that do not accrete into large planets; the asteroid belt and the Kuiper Belt constitute the debris disk of our Solar system. Over billions of years, the remnant planetesimals disintegrate back into small dust grains, the majority of which escape back into the interstellar medium. In this talk, I will describe our current picture as well as outstanding problems in the dynamical transport of dust and solids in the various steps of this cycle of dust-to-planets-to-dust. I will emphasize recent work on this topic with graduate student Amaya Moro-Martin, and current efforts on the astronomical detection of exo-solar debris disks and their planetary systems.