Disable login on multisite web sites
You can have a single login point which you can redirect to from all sites in the network, and then redirect back to the subsite after a successful login. We did something similar for the WordCamp.org network: http://meta.svn.wordpress.org/sites/trunk/wordcamp.org/public_html/wp-content/mu-plugins/wcorg-global-login.php This will probably only work for subdomains, since you can’t really set a cookie for a different … Read more