To Swithch User on a Locked Mac

A while ago I wrote on how to make a Mac available to other users while your own is locked here.
But my favorite guest user found much simpler way.

I dont need to leave the computer with Login Window open to make it available.
On the lock screen when Mac OS automatically locks my user (there are such Security settings) there is a button... Switch User...
:D
Yes, it is sooo simple and it was built in Mac OS X :)))
And yes, my favorite guest user has used Mac just couple of times and knows almost nothing about computers. I am m.sc.comp :))
Dont assume anything, just look eyes wide open - Mac just works :))