A multi-color pen includes a multi-segmented pen body including a longitudinally extending cylindrical hollow tube having a longitudinal axis and a plurality of cylindrical sub-assemblies each of which includes a supply of writing material and a writing point connected to one of the supplies of writing materials. An eraser is disposed at an end of a hollow tube and is shown with a removable cover. The cover may include a compass or a digital thermometer in place of the digital clock. In addition, a rotatable pocket clip extends from the top of the cover and includes a ruler having a straight edge and graduations of length as well as a knife blade or letter opener that is rotatably separable with respect to the ruler.