Voice interfaces

Speech-recognition interfaces for computers would be good for choosing between many items. I specifically would like to see it for switching betwen applications (MacOS X already sort of does this) and switching between different windows (or buffers, or tabs) within an application. One would need a way to record the name of "this buffer". Perhaps there is something special in its good for changing or choosing among things which don't have a "constant" name. Because if it had a constant name, you could define a shortcut (or bookmark, or hot key, etc.) for it.