Open-With Manager lets you edit the list of file types a given application thinks it can open. This is most useful with regard to the Finder's "Open with" context menu; and it also affects the way applications behave when you drag files to their Dock symbols.
Behind the scenes, Open-With Manager works in a way that's quite similar to Service Scrubber. And to be perfectly honest, Open-With Manager is in fact Service Scrubber's well-hidden, slightly older twin brother. That's why the restrictions detailed for Service Scrubber in this blog entry apply to Open-With Manager as well. When running on Mac OS X 10.5 or later, Open-With Manager will not edit signed applications.
Please note that there may never be a final Open-With Manager 1.0. Use this application at your own risk. And if you don't know what "editing an application's info.plist file" means, you might be better off not using it at all.
We do not recommend using this app if you're using OS X 10.5 or newer.