I set up lots of servers with common user accounts. I like to use public key only authentication, but in order to initially set their account passwords, I have to email them a password and then let them change it.
This adds an extra step so I borrowed an idea from +Ben Tuttle
who has a webapp that generates digest passwords, and whipped up a similar application to generate shadow passwords for users.
They can enter their password and send me the salted hash. It is a little more secure and they don't have to share their password.
This way, they have a password set initially on the system and don't have to actually share this password.
Try it out: http://shadow.heyhomeslice.com/
It is powered by Flask and Python and uses Zurb Foundation Bootstrap to make it a little prettier.