How about a mouse which can be molded into any shape which you desire? This was probably the last thing which would have occurred to my mind but here is Lite-On which can take the shape of your hand i.e. you don't have to adjust to it rather it adjusts as per your wishes.

It is different from the run of the mill mouse which we use in our everyday lives since it has been created from non toxic clay with a covering of polyurethane blend fabric and nylon. Having a self retaining shape you can design it as per your convenience in numerous designs and colors. Since the scroll wheel and selector buttons are stick on parts one can easily position them anywhere they like. RFID technology has been implemented for communicating with the flat base section of the mouse. You might be getting eager to own this device after reading all this but up till now the launch date has not been announced therefore you will have to wait with baited breath for its launch.