Setting the self-timer on a digital camera allows a photo to be taken without someone having to press the button. This means everyone can be in the picture. The Canon Rebel XTi has a 10 second timer, and can be activated in a few simple steps.
Push the switch on the top right of the camera into the "On" position.
Press the lowest of two black buttons on the right side of the LCD monitor.
Click the left arrow button to select "Self-timer/Remote Control." This will activate the timer.