change default app for certain files (Mac OS X)

This may seem like a dumb question, but how do you change the default application to open a file on a Mac? I have OpenOffice.org, NeoOffice, and Microsoft Word on my computer, and I would like to have OOo open the files from all of them, but I don't want to have to uninstall my other word processors.

I figured out how to do it for a single file: right click on the file; in the menu, select "Open With"/"other..."; find the application, select it, and also select "Always Open With" and click OK. The problem is that this only changes the default app for that single file only and I can't see a way to extend that setting to every file of that type on the entire computer.

Thanks,

Click on the file once, hit Command I ("Apple key" and 'i'). Near the bottom of that screen that pops up will be a section titled "Open With". If you don't see any details, click the tiny triangle next to it so that the section expands. You can click the name of the default application and choose "other" from the drop-down list, then search for the app you want to use. Finally, click the Change All button right below the name of the new application on the Info screen.

BTW do all this from a Finder window. Don't try to do it from inside an application.