Illuminate a Clear Path to Completion
Luke Wroblewski presents the findings of a usability study on Primary & Secondary Actions in Web Forms. What's interesting about the results is that participants performed the task the quickest when there is no visual distinction between the Submit and Cancel buttons. However, in discussions with the participants they said they liked the visual distinctions better as it assured them they were clicking on the right choice. The analysis then is sometimes it's better to slow users down if it will results in less mistakes.

