Between the late nights and the inside jokes, here are some ways you can spot an improviser from a mile away.
This man is basically God.
Source: en.wikipedia.org
One of these places is probably your Mecca (or at least your second home)...
There are plenty of other improv theatres around the country (like the PIT in NYC), but these four theatres/schools are the powerhouses.
...and you will readily spout off many facts about the history and philosophies of the different training centers...
Via: wfmu.org