I would like to be able to access a Drupal site as a given user/user-type (maybe using Masquerade) and from their view of the site be able to inspect how/where the page's configs/scripts/modules/nodes/etc were loaded from.
Background: It's possible in the next week I'll need to take over 10+ existing Drupal sites and most likely the maintenance for the sites will be driven by request like "On this page, I'd like to change this." While it's likely that I'll just have to use what I know of Drupal and hunt down where/how the given page elements are being created/managed, it would be nice to have the option to inspect how/where a given page element is being set within Drupal given a URL and the user that accessed it; think Firebug for Drupal.
If possible. it would be nice if this worked for 6 and 7, since the sites I believe are in 6, but will likely be ported to 7.