MIT researcher Pranav Mistry shows off a mouseless mouse concept:
As the computer mouse has remained largely unchanged over the last decades, we have become increasingly proficient at operating the two-button mouse. Recently, various multitouch and gestural interaction technologies have been explored as means to implement alternative methods to interact with a computer. Despite these advances in computing hardware technologies, the two-button computer mouse has remained the predominant means to interact with a computer. The Mouseless invention removes the requirement of having a physical mouse altogether but still provides the intuitive interaction of a physical mouse that we are familiar with.
Mouseless consists of an Infrared (IR) laser beam and an Infrared camera. Both IR laser and IR camera are embedded in the computer. The laser beam module is modified with a line cap and placed such that it creates a plane of IR laser just above the surface the computer sits on. The user cups their hand, as if a physical mouse was present underneath, and the laser beam lights up the hand which is in contact with the surface. The IR camera detects those bright IR blobs using computer vision. The change in the position and arrangements of these blobs are interpreted as mouse cursor movement and mouse clicks. As the user moves their hand the cursor on screen moves accordingly. When the user taps their index finger, the size of the blob changes and the camera recognizes the intended mouse click.