By improving the user experience, admin_menu.module and admin.module help tell clients the real story about Drupal.
Until recently, Drupal's administrative interface has been a big hurdle, and I don't mean limited capabilities or functionality problems. I'm talking about a presentation hurdle. Too often clients miss the power of Drupal simply because the default admin interface doesn't effectively bring commonly-used controls to the surface, leaving first-time users underwhelmed and confused.
At Aten Design Group, we tend to prototype in Drupal early in development and get our clients engaged with the prototype as soon as it is practical. This approach provides several advantages - a shorter feedback loop, a gentler learning curve, and a transparent development process. But for many of our clients, this requires a conceptual leap past the default interface to grasp all that even the simplest Drupal prototype has to offer. We work hard to prepare clients for the leap, but things could be so much better, and thankfully there are a lot of talented folks pushing Drupal's administrative user experience forward.
First up, admin_menu.module
The admin_menu module brings all the options below "administer" into a low-profile dropdown menu at the top of the website independent of other themes being used. In our experience, the results have been great. Clients can easily get the lay of the land by quickly drilling down through the menu tree without leaving the context of the public website.
The latest contributed admin UI project, admin.module, provides a more immersive experience based on some of the work done by Mark Boulton and Leisa Reichelt for the Drupal 7 User Experience Project. The interface utilizes a control panel-style theme with a tiered top-level menu featuring a slightly recategorized set of commonly-used administration options. Prominent icons for each menu element help illustrate and bring clarity to the wide range of options. While acting as a real-world proving ground for new ideas from the D7UX Project, admin.module also allows developers building Drupal 6 websites right now to show off Drupal's powerful administrative tools to the uninitiated.
Like most of the community, I have high hopes that Drupal 7 will provide an even more elevated user experience for administrators, among other things. In the meantime, these two modules have taken significant steps toward a UX that demonstrates Drupal's capabilities.