Bonus points if it's a script to show you all global-type changes which occurred within a given time window.

Usage scenario: You look at a graph with an abrupt change. You run the script, indicating when the abrupt change occurred, and a window (30 minutes would be a reasonable default). The script then finds all CLs which occurred in 'global' repos (like infradata, puppet, build, build_internal, etc.) and presents them as a diagnostic aid.