Masquerade does what I want in the background. I just want to change the user interface a little and am happy to work on an add on module if needed.
I want to use the IP Login module to log people in to user accounts with a specific role. That role gives them the option to masquerade.
In the user interface, I would like to offer the standard login block to users who are already logged in and offer the standard logout block when they are logged in as someone else.
I am reading http://drupal.org/node/1171500 and will think about it to handle the role requirement.
The people with the masquerade role cannot login to users with the masquerade role.
Has anyone tried this?