'Remove all hyperlinks from the active sheet
Save it, return to the worksheet, press Alt+F8 to open the macros menu (Tools -> Macro -> Macros otherwise) and run the Macro of the same name as the subroutine above. This should delete all your hyperlinks. Unfortunately, this will most likely remove all other special formatting in the cells as well. If you have a really large worksheet, it will most likely cause Excel (XP and earlier at least) to crash, so you should really save your work immediately before you do this (or before you add the Macro to the sheet).