RCDefaultApp is the creation of rubicode, and is freeware for MacOSX. This preference pane utility basically allows you to set the default application to open whatever extension or url that you desire. You can even set it to be one of the applications that can open it, but is not the default application.
You can also set this same utility to control certain media applications and have certain things launch. For example, if you plug in a webcam, then iPhoto will launch. Or perhaps you want to watch a DVD but not with the default player? No problem. RCDefaultApp can set the player application that you like to use.
Creativetech < rubicode