Portable Firefox CX is a portable profile switcher written for Mac OS X in ObjC/Cocoa. It's designed to give a simple interface to execute a local copy of Firefox.app with a specific profile, choosen from a list.

PortableFirefox CX ships with Firefox 1.5/Mac included. You can easily change the version of Firefox with another simply changing the included app.
If you want to create or use another profile, just copy from Finder the included profile in another folder under /profiles/ with a different name. The name of the folder will be the one displayed inside the application.