I think it would be good if browsers came with an option to mask or don't mask passwords. But I don't know if it would work, since the users who would find and change that option would be the heavy users, that have almost no trouble with passwords.
If only that option could be easily showed and asked for simple users: a little icon within password boxes showing if it's masked or not, and a hotkey / click on the icon to toggle it on/off.
It's fairly easy to do actually, if you're willing to accept the cheat I've used in the past.
You can read the input value with Javascript, so if you add an 'unmask password' button, then that button should effectively replace the input type=password with an input type=password and populate it with the values previously stored in the password element.
There are a number of ways to do this, but switching out elements was the easiest for me -- of course, browsers have come a long way since that implementation. YMMV.
I was once typing in my password on a box I forgot I had converted to Dvorak. I was almost panicking because I was so sure I was entering the password correctly.
If only that option could be easily showed and asked for simple users: a little icon within password boxes showing if it's masked or not, and a hotkey / click on the icon to toggle it on/off.