Many of us will remember the miniature submarine in which Rachel Welch travelled through the human body to zap a bloodclot in the film Fantastic Voyage. Some will be disappointed to know that this is not going to be possible and will never happen. But the good news is that nanotechnology may be able to help do the job of targeting and zapping diseases in our body much better than the Proteus ever could, and without the risk of becoming submarine-sized halfway to finishing the job