I love Colophon and its use as a way to show how a site is built (at least, which modules are involves), and promote the good work of module makers. We use it on the new drupaltalks.com for just that purpose.

It's one thing to promote and teach, but it is another to show which (potentially out-of-date and with security vulnerabilities) a site has before it has a chance to upgrade; having an option to only show the major Drupal version (6, 7, etc) and another to hide the version numbers from all modules and themes would be great.