I just discovered, (here I think!) that holding the ALT key down and selecting 156 on the numeric keypad gives me a £ sign!!!
I used to do that until I went to VISTA, now I have to go to Start/All Programmes/Accesories/SystemTools/CharacterMap then I can select the £ sign by copying it. It says I can use Keystroke Alt+0163 ( like your 156 ) but it doesn't work.
I blame Bill Gates.