Do you have users that like to forget their passwords? Here are 2 methods for getting new ones (the passwords, not the users!)

% drush upwd username

And here is how to create a one-time login link for a user that has forgotten their password. (again?!)

% drush user-login username

The output will be something like this:

http://example.com/user/reset/17/13425300/c18Zh_dYH2XxHzBcJU9jU

Just email that link to your user and they can log in and reset their password.

If you know their email address you could be clever and do something like this:

drush uli username | mail -s 'Reset password request' useremail