Be stars are rapidly rotating, massive stars that eject mass into a circumstellar, gaseous disk. The mass loss process is partially the result of fast spin, but because these disks are inherently time variable we know that other mechanisms also play an important role. In this talk, I will review the observational properties about these remarkable stars and discuss the evidence that implicates past mass transfer in an interacting binary star system as the source of their large angular momentum. I will discuss the recent work at GSU on Be stars with neutron star companions and the first angular resolution of Be star disks in the near-infrared with the CHARA Array interferometer at Mount Wilson Observatory. Finally, I will describe our current multi-faceted program to model Be star disks and to search for evidence of unseen companions.