There are many more ways you can make your web sites more accessible. The key to understanding accessible web design is to understand your users' needs. This means understanding your content and audience. If you make an effort to make your web pages more accessible, your users will thank you for it. Many of the problems people with disabilities have will be reflected elsewhere in your user base.
Accessible design is good design.
By taking steps to ensure they reach your content, you will be making it easier for everyone. It's a win-win situation.