Once only the subject of science fiction, it is increasingly likely that in the next few decades many of us will have computers in our own homes. Although the science fiction writers imagined these would probably be the size of of an entire room, you can already purchase powerful machines that resemble nothing more than a typewriter keyboard which connects to your television set. Mainly used to ease otherwise laborious accounting chores, you can also use them to play games and, if current developments continue, you might soon be using one to draw a picture or compose a piece of music.