Not sure where you have to log out exactly
Log out in the building
Log in
If not under the ground move somewhere else
Repeat

You can see almost completely out the building but can not be seen when inside, obviously.

The problem is that, according to my knowledge, you can play around on an empty public server until you finally do end up under the ground. When you log out there and back in on another server, you will always be under the ground.

SUGGESTION: Make it possible to get player names even if they are dead.