John Nack, the Photoshop product manager with a background in web design, has always (as long as he’s been in office) pushed for more extensibility and custom configuration of the Photoshop interface.
As a result, in Photoshop CS4 we now have flash-based panels that can be built from scratch by third party developers.
But it gets better. Very soon now, you can ‘roll your own’ Panel in a snap with Adobe Configurator.
The application lets you pick and choose (literally drag and drop) among Photoshop tools, menu items, scripts and actions, and it even lets you include stuff like instructional videos, before it ‘bakes’ a new Panel that you can import into Photoshop CS4, and share with the world. Presto! All of your most used tools in one customized Panel. Pretty damn cool.