This weekend I ran across the word "hooah," in use by the fella who would be my brother-in-law if I went and got married, which I ain't gonna do, and she ain't either.

In any case - he is in the Army reserves (about to go active...yikes) and introduced me to this term. It is apparently used in the Army to mean just about anything - he likened it to the accursed term "smurf" and its widespread usage in the early '80s or so. After googling around a bit, I found this list of suggested meanings, which I assume is not intended to exclude other possible meanings:

1.Good copy, solid copy, roger, good or great; message received, understood.
2.Glad to meet you; welcome.
3.I do not know, but will check on it.
4.I haven't the vaguest idea.
5.I am not listening.
6.That is enough of your drivel--sit down.
7.Stop sniveling.
8.You've got to be kidding.
9.Yes.
10.Thank you.
11.Go to the next [briefing] slide.
12.You have taken the correct action.
13.I don't know what that means, but am too embarrassed to ask for clarification.
14.That is really neat, I want one too.
15.Amen.

What I couldn't find is where the heck this comes from. I was also curious as to when it came into use. I know we've got at least a couple of former servicemen here (BobY, Dr. Bill), but am not sure if any of them were Army - and apparently other branches of the armed services have their own equivalent terms.

So - any ideas where the Army got "hooah" or other suggestions for use of this flexible word?