New on the SitePoint "Web Tech" blog today is a post by Craig Anderson about friendlier passwords.
One aspect of web applications which is almost always overlooked when it comes to accessibility is how easy any randomly generated string might be to read. If you're lucky enough to have near perfect vision and have no learning or cognitive disabilities such as dyslexia, you mightn't suffer from any problems reading randomly generated strings, but for many users distinguishing between zero and upper-case Os, ones and lower-case Ls, and even the letters b and d can be difficult.
He includes a simple little PHP script that pulls letters and numbers from a pre-defined "friendly" array that can be read more easily by those with some sort of visual issue. Obviously, the results would be less secure than some other methods (only so many to go around) but its still a wide enough range for most common uses (around 17 million passwords).