So I'll post it on my blog :)
drush uliOr if your targeting a specific user:
drush uli username
Using drush you can create a one time login link for a user or admin.
This is especially usefull if you want to login to the site without changing the password.
For example if you have a client with a drupal site that doesn't know the administrators pass or doesn't want to change it because you need it.
This can also be used to change the password if you don't know where the password reset link would be send or don't have access to the email address ( anymore )