For anyone who may have read my response above, David Ritchie was kind
enough to point out to me a very dangerous and potentially disastrous
result of my solution in that my code would inadvertantly (and
unknowingly to the user) change formulas to values.

Rowan's code above works fine and avoids the pitfalls of mine.
Additionally, you can check out
http://www.mvps.org/dmcritchie/excel/proper.htm#upper