US to GBP
Along with the changes Jason pointed out in the thread
I've been doing this as well and after doing a entire site search in the source code for "number_format" I changed the following pages from "$" to "£"
Admin > home.php
Admin > orders_Delete.php
Admin > orders_Results.php
Admin > orders_Update.php
Admin > Products_Delete.php
Admin > Products_Detail.php
Admin > Products_Results.php
Email_Templates > admin_receipt.php
There are quite a few instances on some of the pages but clicking on the search results in Dreamweaver will take you to the relevant line of code that needs the "$" replacing.
Hopefully that covers all of the currency changes whether it be to GBP or any other.