SingleClickInstall
Most accessibility features are only used by a relatively small part of the public, and therefore in may not be warranted to have them installed by default. Modularity is a widely recognised strength of Linux, which means you can install and activate just the features you want. Most people prefer a lean and uncluttered system that has just the components they need. Sticking to this principle leads to a less resource-hungry platform, which in turn extends the life of hardware and makes computing more affordable.
However, the task of installing components can be a major challenge for someone with a disability, because it may be precisely these features she needs to operate her computer normally. The optimal solution seems to be to leave these features un-installed by default, but to make it easy to install them. One solution is to make these features available during the install process (see: [Accessibility Aware Installer]), but there should also be simple options for installing these features on an existing setup. It would be helpful to have the most common packages stored on the users hard drive.
Desktop dialogues
Several existing desktop preference dialogues already deal with different aspects of assistive technology (see AccessibilityHowto), most notably the Assistive Technology Support dialogue. This would be greatly enhanced by adding an option to install these features directly from there. Specifically, it should be possible to install gok, gnopernicus and possibly dasher directly from the Assistive Technology Support dialogue.
The standard Gnome keyboard enhancements (such as Sticky-Keys, etc.) has an associated status notification utility in the form of a panel applet. It is often useful to be able to check visually whether one of the modifier keys is active, as the computer's behavior might otherwise seem rather unpredictable. Currently, this feature can only be activated by adding a panel applet in the normal way, requiring that you find it by chance. It would be useful to have a button somewhere on the keyboard enhancement dialogue, which activated this feature.
GNOME Display Manager (GDM)
The latest [http://www.jirka.org/gdm.html GDM] does support accessibility features. This is useful because it allows the user to control of the system from the login on-ward. It seems from the Hoary wiki pages that a substantial reworking of GDM is planned for the next release, so it seems likely that the accessibility features will also be included.
AFAIK, GDM listens for certain keyboard input or mouse gestures to activate accessibility features once these features are installed and certain config changes are made to GDM. It might be preferable to have GDM listen for this input by default and then prompt the user if these features are not available: 'You have requested the screen magnifier. This feature is currently not installed on this system.' ('Click Install' now or 'Cancel'; installation requires password) This would work well on a private system, where accessibility features are already installed, but there may be issues on public terminals. (btw: the input signals are designed so that the average user is not likely to give them by accident; example: press Shift five times)
Command Line Utility
Many blind people mainly use the command line interface for their computing. It would therefore be useful to have a simple text-based script that allowed one to install and configure various usability enhancements.
Public terminals and privileges
On a private system the main user knows the primary password and so is able to install features system-wide. However, on a system installed at a library, school, university, etc. this will not be the case. This can be a limitation for someone who is traveling and needs to use publicly available systems. We should perhaps encourage sysadmins at public sites to install these features by default.