Possible to exclude jQuery? (Because I've already included it elsewhere)

Drupal only manages content for part of my site, and therefore is installed in a subdirectory. The Drupal and non-Drupal pages will use much of the same code, and thus I'll be relying upon include files to make maintenance easier and more efficient.

A single include file will manage much of what goes in the head tag, including jQuery. So, if Drupal is using this include file, the code to include jQuery will already have been made.

So, how do I prevent Drupal from loading jQuery again?