A computer scientist is a person who helps to innovate new applications of computers, in terms of software and (to a lesser degree) hardware. In other words, if there is no known method to do something with a computer, it is up to computer scientists to discover a way to do it.
A fairly well know area that demands a large number of computer scientists is robotics. As a field, robotics is still in its infancy. Many universities do not have a program for robotics. Although we have seen significant advances in robotics in recent years, there is still a long way to go before this field hits its plateau.
Another field that employs a significant number of computer scientists is computer security. The discovery of exploits and derivation of counter measures are extremely demanding in terms of technical knowledge, theories, analytical capabilities and innovation (thinking out of the box).
To be employed as a computer scientist, having a master’s degree in computer science or mathematics is a minimum. Furthermore, having an analytical mind and enthusiasm to solve problems is crucial characteristics of a successful computer scientist.
The demand of computer scientists will see a large increase in the near future. Unfortunately, the quantity of employment is small to begin with.