Excellent node! But a minor quibble: my memories from my intro data structures course are not the strongest, but they suggest that your definition of a post-order traversal is slightly flawed: the Left-Right order of the leaf nodes should be preserved (that is, net should still precede store, and research precede development).
Not a major issue, of course, for an org chart--but it could be unfortunate if that happened to an expression tree. :-) (thanks to maverick for the link, and for confirming that I'm not totally nuts.)
If God had meant us to fly, he would *never* have given us the railroads.
--Michael Flanders 