LoadLevelAdditiveAsync by index?

I'd like to use LoadLevelAdditiveAsync to load each scene from my build settings list, but the method only accepts the scene name, not the build index. I can't find any way programmatically to convert the build index to a scene name. Any ideas?

For the time being, I'm forced to use LoadLevelAdditive, without the Async option.

I found a feature request for this, but wanted to check here for any other work-arounds. http://feedback.unity3d.com/forums/15792-unity/suggestions/177240-scripting-expose-the-build-scene-s-name-list

Unity 3.2 can use an index for this now.