  Elastic form factors provide information about the low energy structure of
composite particles.Recent double polarization coincidence experiments
significantly improved our knowledge of proton and neutron form factors. Recoil
polarization measurements in the p(\vec e, e' \vec p) reaction proved that at
momentum transfers above Q^2 \simeq 1.5 (GeV/c)^2 the electric form factor of
the proton falls significantly faster than the dipole expectation. The
close--to--dipole shape at low Q^2 of the neutron magnetic form factor is now
confirmed by independent measurements. For the neutron electric form factor
\vec ^3He(\vec e,e'n), \vec D(\vec e,e'n) and D (\vec e,e' \vec n) double
polarization experiments have provided model independent results, within their
statistical errors in agreement with the Galster parameterization.
