User-selectable admin interface language?

I like the way that WordPress.com handles the interface language: it’s per-user, and each user can specify what language they want to see through their profile.

Is there any way to do this on a www.ads-software.com blog? My blog will be written by authors from several different countries, and I’d really like them to see the admin interface in their own language.

I’ve looked for plugins, but can’t find anything promising. Wondering if this is just something I’ve overlooked somehow, since it’s been around in WordPress.com for over two years. Or is it the WPMU-like structure that makes it possible there?

Any insight is appreciated!