How to register an application to a uri scheme in Mac OS X

Question

Mac OS Applications can register for custom uri schemes through their Info.plist file by specifying CFBundleURLTypes. In order to add another uri scheme the Application bundle needs to be modified.

The question is: how do I add an additional uri scheme for an already installed application, without changing the Application itself. Bonus points if this can be done from the command line.

Answer 1

I personally use RCDefaultApp preference pane, which is free. I think it manages these CFBundleURLTypes (and more) for you.

It's point and click. I'd like to hear about a command-line option, too.