A good tutorial on making password fields accessible when you’ve got the option to show and hide the input.
A great investigation into the usability benefits of allowing users to fill in their passwords in plain text.
Major caveat: make sure you still offer the ability to mask passwords too.
I concur completely with Luke’s assessment here. Most password-masking on the web is just security theatre. Displaying password inputs by default (but with an option to hide) should be the norm.