Most people realise that Excel can be used to carry out statistical analyses of data but what is not so well known is that it provides an extremely flexible and versatile teaching tool for constructing computer demonstrations. In this paper we first show a number of pre-built Excel workbooks for demonstrating statistical ideas - these illustrate the range of things that can be achieved. Then we show that building such workbooks is quite easy by showing how to construct a useful computer demonstration "from scratch" in just a few minutes, starting with a blank workbook. The aims of the paper are to outline benefits of using Excel for teaching statistics and to encourage other teachers to experiment with their own demonstrations and ideas.