Keyboard Layout adjustments.

I have sucessfully, after many false starts and problems, got Snow Leopard installed on my Dell Studio XPS 1340.

Does anyone know of a way of changing what particular keys produce?

I have a british keyboad layout, and even though I have selected that in the setup, I still have a couple of issues in as much that some of the keys type the wrong thing.

" and @ are swapped round for me. I suspect this is due to the some old standards where some progs are one way round and one is another. I remember my old PC having both charcters on both keys.
Also some of the other non character keys are wrong also.
My |\ key, next to the left shift produces nothing. It functionality seems to be mapped onto the ~# just above right shift.
The ~ charatcer is mapped onto the top left key ¬`, but that still produces a ` on non shift.
This is a little frustrating as I can't actually type a # at the moment which is a bit of a bind when trying to edit scripts.

Anyone know of a utility to adjust the layouts?

!m!