I have the fun job at the moment right now to turn a lot of word documents into HTML, as the client does not have a CMS or want one.
The Homesite keyboard shortcuts are a real treat there (ctrl+shift+p to turn the highlighted section into a paragraph), and the right-click “turn into unordered list” helps a lot, too.

However, what was missing was a keyboard shortcut to turn a line into a heading. What is cool about Homesite 5 though is that you cannot only write your own toolbars, menus and containers with something called VTML, which is much like XUL) but you also have an API to completely script the editor itself. So what I did is write a small headings.js file and attached it to the keyboard shortcut ctrl+2 (ctrl+1 already replaces all special characters with numbered entities – another script I did) via the Options -> Customise -> Script Shortcuts dialogue.
When I now write something like

1Welcome to the last day of your former life

and press ctrl+2 it turns it into

Welcome to the last day of your former life

the number defines the weight of the heading (1 to 6). The script is easy enough:

function Main()
{
var selectedString = '';
var weight=1;
// highlight the current line and store its content in s
Application.ActiveDocument.SelectCurrentLine();
s = Application.ActiveDocument.SelText;
// get the first character and add the tag brackets with that weight
// around the line
weight=s.substr(0,1);
var r='< h ' + weight + '>'+s.substr(1,s.length) +'< / h ' + weight + '>';
// replace the highlighted line with the new one
Application.ActiveDocument.SelText = r;
}
//Following is some textile bug: 

More Information about the API is available at The Macromedia Site.