To login and logout of Extension Mobility via a URL:

https://x.x.x.x:8443/emapp/EMAppServlet?device=SEP6400F1111111&&userid=userid&seq=PIN
https://x.x.x.x:8443/emapp/EMAppServlet?device=SEP6400F1111111&doLogout=true

For when your provisioning app hits the craps and you need to do it remotely :).