Official Google Blog posted a blog for their accessible services.
It is good to see all the services that they have as a list cause there so many of them now.
The List and more
* Web Search: Result pages include headers to delineate logical sections.
* Accessible Search: Promotes results that are accessible.
* Book Search: Full-text access to public-domain works.
* Gmail: A simple yet functional HTML mode that works well with screenreaders.
* Gmail Mobile: A lightweight user interface that is also speech-friendly.
* Google Maps: Easy-to-use textual directions.
* Calendar: A functional, yet speech-friendly user interface.
* Audio Captchas: All services that use Google Accounts provide an audio alternative for the visual challenge-response tests that are used to distinguish humans from machines.
* Mobile Transcoder: A mobile lens for viewing the web that produces accessible views.
* Google Video: Allows uploaded videos to contain captions/subtitles in multiple languages for viewers who are hearing-impaired or unfamiliar with the original language.
* Google Talk: IM clients inside a web browser can pose accessibility challenges, but the use of the open Jabber API means that Google users can choose from a variety of Jabber clients, many of which work well with adaptive technologies.
* Web APIs: Many Google services offer high-level web APIs that aid in authoring mashups; this provides a means for creating highly customized accessible views.
* 1-800-GOOG-411: Here's an exception to the rule that we deliver most things through a web browser. Our experimental Voice Local Search service lets anyone who can speak into a phone search for a local business by name or category; get connected to the business free of charge; get the details by SMS if you’re using a mobile phone. (Just say "text message".)
Official Google Blog: Overview of our accessible services