Original idea by David Hager
(Please refer to the Spreadsheet Page by John Walkenbach for more detail, http://j-walk.com/ss/excel/usertips/tip045.htm)
This is a way to find which cells have formulas by using Conditional Formatting.
On the top menu define a name such as "Cell has formula" with Insert, Name, Define then enter =GET.CELL(48,INDIRECT("rc",FALSE)) in the "Refers To" box.
Then use Conditional Formatting, select "Formula Is" and enter "Cell has formula", then format to your preference. All cells with formulas will now show in this format.