Many of us are still haunted by our colleagues' Excel dependence. Even though I remembered the ghastly spreadsheet's I've been sent, I didn't expect to see as many truly horrible ways to use Excel as you have shared. Clearly someone needs to teach folks how to use a spreadsheet. From dropping images in it and sending it via email to creating a blog wireframe using Excel borders and shading, your answers had us all giggling.
What is the worst use of an Excel spreadsheet that you have seen?