In a multisite setup, when users are visiting a blog/site that there are not a member, I would like to display a link to "HOME" that takes them to their "primary" blog.
I know how to determine if a user is or is not a member of a site with the is_current_blog_user() function. The part I am having a problem with is correctly setting the url/path of the "HOME" link to the current users "primary" blog.
<a href="<?php this_is_the_path_to_users_primary_blog();?>">HOME</a>
I have found the get_active_blog_for_user (http://codex.wordpress.org/Function_Reference/get_active_blog_for_user) function, and this seems to be a good place to start. But I feel as though I must be missing something, and this must be easier than I am making it.