Thanks to all who pointed out that BIAB has a vocal wizard. Now that it's been mentioned, I remember seeing it before, thinking that it would be useful. In fact, it sounds like exactly what I'm looking for.

Ian,
my current method of determining key is to experiment with the capo. Your idea is certainly not "too simplistic".. I generally prefer simplicity. My biggest problem is that I work such long hours that when I finally have a few minutes to play I want to solve the analytical problems quickly so I can spend more time on the creative stuff.

Noel,
I have had some luck in those keys, depending on the melody. It should be noted I've also crashed and burned in the same keys with different melodies. Hence, the question that started the thread...

;-)