Random New User Password Wordpress Plugin - Rating, Reviews, Demo & Download
Plugin Description
Inspired by http://wordpress.org/extend/ideas/topic/random-password-for-new-users and a couple of hours of free time, this JavaScript-powered plugin adds a button to the Add User screen, which, when clicked, generates a strong random password for your new user. This should shave off a couple of seconds of your time when creating a new user.
Props to @1Popov for the random dice image.