phranque - 3:14 am on Mar 15, 2009 (gmt 0)

there are a couple of threads in the Accessibility and Usability [webmasterworld.com] forum that discuss the use of accessibility techniques but don't directly address your question:
accessibility and <h1> header images [webmasterworld.com]
Web Content Accessibility Guidelines (WCAG) 2.0 [webmasterworld.com]

i am moving this to that forum - perhaps someone with practical experience will respond there.