Encryption

Dark Neuron writes: My institution has thousands of computers, and is looking at starting an IT policy to encrypt everything, all hard drives, including desktops, laptops, external hard drives, USB flash drives, etc. I am looking at an open source product for Windoze, Mac, UNIX, as well as portable hard drives, but i am concerned about overhead and speed penalties. Does anyone have experience and or advice with encrypting every single device in a similar situation?