How can I ensure that I'm logged out of Google Latitude? When in Google Maps, when I go into the menu, I see "Join Latitude" option next to Latitude icon.

When I am on Google Latitude web site, it tells me "Location sharing is not turned on"

Does that mean that I am 100% logged out of Google Latitude? 

The reason I ask is that I was experiencing major battery drain via Google Maps, and many people on forums heavily recommend signing out of Latitude as a solution. However, it seems that my Latitude is already off.
If you see "Join Latitude" then your latitude options are already "off". If you also now see "location sharing is not turned on", then your account is not set up to share the location information and it will not be sharing the information. 

If you don't already, turn off wifi &amp; gps when you are not using them, mpas will be less likely to try and get "pin point" information if you do not have these running.