It's like a multi-user environment for just one application.
Use TweetDeck and wish it supported multiple accounts?
Have a laptop you use for work and personal use?
rooSwitch makes it easy to manage profiles of almost any application for at work or at home
Have an application that only supports one library of data?
rooSwitch will enable you to manage multiple libraries.
Are you a developer, QA or support person for an app and wish it was easier to test the new user experience and other canned scenarios?
Drop the app on rooSwitch and let it manage multiple versions of that applications preferences, settings and data files for you.