I was recently asked: "How can I hide the side nav bar on the main homepage layout ?? I want to be able to use the side NAV with in the team site etc etc, but I don't want it on the front page.. "
There are a couple of ways to do this in SharePoint 2010. If you are using a non-publishing site you can add a Content Editor Web Part to the page and add the following to the HTML Source.
Basically the CSS above hides the left navigation Div, and then sets the content area to not have a left margin.
Once you are done, simply modify the web part and hide it on the page.
If you are using a publishing site for your homepage simply add the same styles specified above to a custom page layout. That way if you have a need for other pages that do not need the left side navigation you can re-use the page layout.