ACT Hangar Manager includes tools for configuring aircraft, panels, flights and sounds as well as 'hangaring' aircraft so as to only maintain active those needed for a given flight whether flyable or AI. Click on Read More for the full story.
Hangars are organized by aircraft manufacturer. There is also an option to maintain a local database from which to select which aircraft to load rather than searching hard-drives for CFG files.
ACT Hangar Manager is non-destructive: hangared aircraft can be restored by renaming *.HGR to *.CFG and moving 'hangared' directories back to your FS9 Aircraft directory.
Hangar manager also works with CFG files in XML format.
An FSX version of ACT is in testing at LogiqueWerks.
The aircraft config tool 'Hangar Manager' for FS2004 is now freeware at http://www.logiquewerks.com