Our newly developed fluorescence resonance energy transfer (FRET) based technique, fluorescence nanotomography (FN), is used to determine the morphology and dynamics of some soft materials and bio-molecules by attaching donor (D) fluorophores and acceptors (A) to the investigated structure and using fluorescence lifetime measurements to reveal the D-A distance distribution function rhoDA(r). We report the effect of the limited sizes of the donor and acceptor, effect of porous polymer, and molecular structure and phase transition in phospholipid bilayers.