Gravitinos are the hypothetical supersymmetric partner of the Gravitron - the possible particle behind the gravitational force. Gravitinos are nearly massless with a spin of 3/2 and are formed by gluons smashing into each other in the reheating period after the inflation period in the early Universe. Also, it is hypothesized that gravitinos can be created by decaying neutralinos during the inflation period. These particles are very new and not very much is known about them because they are so hypothetical. They have a mass of about 1 eV and are mostly found in the halo of galaxies. As far as being a good candidate for dark matter, it is hard to tell because so little is known about them. (7)