What should novices know about Drupal and accessibility?

I'm trying to develop a presentation about accessibility and Drupal. The idea, posed to me by Mike Gifford (mgifford), is that it should be a basic presentation that many different people could give give at various conferences—Web camps, Drupal camps, geekouts, whatever.

So here's where you come in. I need ideas. Tell me about:

• The Core accessibility features you find most useful.
• Modules, either core or contrib, you find most useful in supporting accessibility.
• Other modules that have accessibility features you really appreciate.
• Accessibility issues you most wish could be fixed in core.
• Contrib modules that most need help with accessibility.
• Projects you've worked on in which Drupal has helped you overcome significant barriers to accessibility.
• If you have a disability, features in Drupal's admin interface that have made it possible for you to build websites.
• If you administer a website in which there are many different contributors, features in Drupal that make it:
  • Easy for people with disabilities to contribute content.
  • Easier for people who contribute content to make that content accessible. (I do want to hear about things Drupal does behind the scenes, but I'm especially interested in things Drupal does to steer them in the right direction when they have to decide what to do.)

Obviously, not all of that can make it into one presentation. But I'd like to gather enough information that we can build several different levels of presentations, or presentations that each deal with a separate angle on Drupal's support for accessibility.

So, what do you say?