All screen readers that I know of have keyboard shortcuts that allow the user to navigate within a web page by jumping from heading to heading. This can really speed things up when you want to skip to a particular section of a page.
Being able to navigate by headings would also be very useful to sighted people who do not use a mouse, but unfortunately very few web browsers offer this functionality. The only graphical web browser I know of that has such functionality built in is Opera, while Firefox can get it by way of an extension.
More at: http://feedproxy.google.com/~r/456bereastreet/~3/gbfIiMlnl7k/