Preferred way to use favicons?

This is what I always use:

<link rel="icon" href="favicon.ico" type="image/x-icon" />  
<link rel="shortcut icon" href="favicon.ico" type="image/x-icon" /> 

The second one is for IE. The first one is for other browsers.

You can use HTML to specify the favicon, but that will only work on pages that have this HTML. A better way to do this is by adding the following to your httpd.conf (Apache):

AddType image/x-icon .ico

I think the most reliable method is the simply added the favicon.ico file to the root of your website.

I don't think there is any need for a meta tag unless you want to manually override the default favicon, but I was unable to find any research to support my argument.