Multi-user/role testing, best practices Am loving using Drupal 6 for creating a site with more than one user "type", with different Content Profiles, different Roles with associated Permissions, different access to nodes etc. My current site has 3 different roles - Recruiters, Candidates and a Simple Administrator (as a reduced feature subset administrator, to limit the amount of damage that a non-technical administrator can do to the site, yet still do things like edit the outgoing emails, add/remove users etc).

I was wondering... when I am testing, I am currently using multiple browsers (dev in Firefox, Testing one user type in Chrome, one in ie9) to get around the "current" session issue (you can only be logged in as one user). What techniques do people use to test on multiple roles simultaneously? Is there, for example, a Firefox plugin or something else to isolate different browser based session cookies in different tabs?
You could try the Masquerade module for Drupal.  It allows you to switch users if you have the right permissions, so you could switch mid-session to a user with a different role etc.  

Another thing you could try, though non-Drupal, is multiple sessions within Firefox.  Look here, here and here to see if that could help you.