A few years ago, Apple filed a patent for a "Wide Touchpad On a Portable Computer."
Today, we can see that the company has been granted the patent. It's an interesting concept because it's designed for laptops. The idea is to let users move their cursor around easily from any position where the laptop's handrest is located, such as what's pictured below:
The touchpad is designed to recognize the difference between intentional input, such as a finger trying to move the cursor, and unintentional input such as the palm resting on it.
The description below says more:
In one exemplary embodiment, a portable computer having a display assembly coupled to a base assembly to alternate between a closed position and an open position. Palm rest areas are formed by a touchpad disposed on the surface of the base assembly. In an alternative embodiment, a touchpad disposed on the base assembly has a width that extends substantially into the palm rests areas of the base assembly.
According to the patent, this could also be practical when using larger laptops where the user's hands may not be as close to the trackpad, which is placed in the center.
[Via Free Patents Online]