|1.||the moose has left the building|
The term is a neologism. It was a joke 'Internet term' which was first used by "Friday Night Cranks" and has since been (rarely) used by fans of the show. It was supposed to be a common "figure of speech" used on Myspace (as told on the show) and was meant be mean, "Where do you live?" when stated. Similar to an euphemism.
The term "can I take a bite out of your taco?" was also created by Friday Night Cranks at the same time this one was.
Bob: The moose has left the building