The hardest part was figuring out how to embed the code on my site.  I first tried pasting it into the editor, but it showed up as raw HTML code.  I then tried using the Google Voice Widget Plugin but I could only figure out how to place the widget in a sidebar rather than on a page.  That's too bad -- it has some handy features, like setting hours when calls should automatically go to voice mail.  Finally, I found How to Use Google Voice on Your Website which had the handy tip that you need to use the HTML (source) editor, rather than the visual editor, when you paste in the code.  Duh.  Worked like a charm.