How about recording your favourite smells! The Tokyo Institute of Technology in Japan has engineers working on exactly that.  They are building an odour recorder capable of recording, for playback the odour of anything.  For example point it at a freshly baked pie and it will analyse its odour and reproduce it for you using a host of non-toxic chemicals.

The whole idea sounds very cool and I can imagine sitting back with my eyes closed and reliving moments with my nose but something about the chemical reproduction does make me worried.  I wonder if there will be any long-term health risks.