I don't know how I feel about this. To tell you the truth, I already did some small use test with 2 users (medium and advanced). And they both have a bit of trouble understanding what that sign was for.

It also didn't help the fact that the outline of the password was distracting: http://dl.getdropbox.com/u/4651065/files/2012/3/Screen%20Sho...

The idea itself is interesting, though without previous explanation or knowledge it's just hard to guess what it is about.