Create a repeatable Drupal install?
Have a look at the Drush make project:

http://drupal.org/project/drush_make

There is also a companion website at:

http://drushmake.me/

This website allows you to select the modules you want to package with Drupal, and produces a Drush-ready makefile.

There are other varieties of this functionality out there, so I advise experimenting and testing with your specific configuration.