The most obvious use of the camera timer is simple - to get the photographer into the shot! If you're alone, the timer makes it easy to take a shot of yourself. Set the camera on something sturdy and at least a foot or two off the ground, such as a rock or a table. Make sure the path is clear between the camera location and where you'd like to stand for the photo. Once you've activated the timer, get yourself into position and wait for the camera to snap your photo.
Get creative: Place yourself off to the side of the photo. Try looking away from the camera so that the photo shows your profile or your back. Interact with the scenery for a "candid" look. The timer allows you to get creative by doing something other than the typical, forward-facing, smiling self-portrait.