Is there a is_user_logged_in() for multisite?

Is there a is_user_logged_in() function for WordPress MU / Multisite (3.0+) where I can add in the network site ID like is_user_logged_in(2) where 2 would be the site_id?

Update:

After a little digging I came up with the code below. Unfortunately it does not work.

//don't use this. does not work.
function mu_logged_in($blog_id){
    switch_to_blog($blog_id);
        $status = is_user_logged_in();
    restore_current_blog();
    return $status;
}

anu’s answer and comments are good.

also, make sure you have the cookie domain set correctly in the wp-config.php file 🙂

Yes, and no!

The way users work in a multisite scenario is that there is a single pool of users, who are then associated with blogs.

So, logged in status is common across all the blogs, but you can use is_blog_user($blog_id) to determine whether the current logged in user is a member of that blog. An example:

if (is_user_logged_in()) {
  if (is_blog_user(4)) echo "Current user is a member of blog 4";
}

Codex page for is_blog_user()