cwh_link_to_home is a Textpattern plugin that provides replacement tag for <txp:link_to_home /> that includes a new format attribute which provides the ability to set the link format as a <link> tag suitable for placing in the <head> of any page on your site. You can do this by setting the attribute format to link, like so:
<txp:cwh_link_to_home title="Home" format="link" />
which will produce something similar to:
<link rel="home" title="Home" href="http://yourdomain.tld/" />
This tag also shares all of the same attributes as <txp:link_to_home />. For a complete list of applicable attributes, see this Textbook entry.
For a further explanation of the benefits of using <link> tags for your site's navigation, please see Day 9: Providing additional navigation aidsfrom Mark Pilgrim's Dive Into Accessibility.
You can download the plugin below: