Chances are you have a backquote (`) above your tab key in the upper left of your keyboard. (This is the same key that produces a tilde, ~, if you press Shift when you press it.)
In Excel, Ctrl+Backquote toggles on and off the display of formulas within cells.
(P.S. Sorry for the long time in between posts.)
I love this website! This is a great application of what I call information efficiency management. I hope you are able to pick up regular updates in 2009! Happy New Year!