The BBC has been working to produce ‘Draft Mobile Accessibility Standards and Guidelines’ for use within the organisation, but which will be of wider interest.
An article at http://www.bbc.co.uk/blogs/internet/posts/Accessibility-Mobile-Apps gives some of the differences to standard desktop web issue and also invites feedback. The draft itself is at http://www.bbc.co.uk/guidelines/futuremedia/accessibility/mobile_access.shtml.
(Source: E-Access Bulletin)