Does google maps javascript api-key (v3) need to be kept secret in HTML checked into github and if so, how?

Question

Looking at the developers guide for the Google Maps Javascript API v3 it explains first about how to obtain an API, then shows examples of including that key in the HEAD sec

Answer 1

According to http://code.google.com/apis/maps/signup.html, version 3 does not need a key. "The Google Maps Javascript API Version 2 has been officially deprecated as of May 19, 2010. Version 3 does not require an API key."