Thanks! That was fast. I'm definitely interested - most of my apps are translated by users and I've been emailing xml files back and forth. Not fun for anyone.
I started that way, too. I kept sending XML files to users and they kept sending Word documents back to me. There are quite a few competitors -- such as <transifex.com>, <poeditor.com>, <crowdin.net> and <getlocalization.com> -- which are all very well done. However, I felt that a free (and even self-hostable) solution would be desirable. Localize, compared to all the other platforms, has the simplest ways for non-tech users to contribute translations. It's even possible to accept anonymous contributions. That way, I've localized an app to 48 languages, so it definitely seems to work :)