I want to distribute my application around the world and allow users to perform their own translations into their native language.

I want the users to be able to use the (translated) application immediately without waiting for me to release a new version.

My code is language switchable at run-time and picks up the strings for the selected culture from resource files (e.g. Form1.en.resx).

As far as I can see the only way I can achieve this is to create .resx files named for every language in the world (but with English text in) and allow the user to edit them (maybe with a custom editor).

Any ideas on a different approach or a good .resx translation editor?

I've tried to keep this short, so I'm not sure I've described it fully enough. Please ask for more information if you think you can help.