exposure, your ability to do them is limited. The camera can be set to hold the shutter open for an extended period (30 seconds on my 20D), and exposures can be made while it is open. I have done this in a dark room by manually triggering a flash unit.
I suspect most people simply bring multiple images into Photoshop, and blend them via layers using masks, transparency, blending modes, etc.
Some digital cameras do allow multiple exposures, but I don't know if the Rebel is one of these.
I recently bought the Rebel XT DSLR after years of owning the Rebel film camera. Pretty intuitive to learn since so many of the controls are the same, but... how do I set up for multiple exposures on this digital model? Anyone?