Automatic multi currency display on entire catalog.
Run your catalog in a main currency (or a main and alternate) with the customer having the option to turn on an additional currency throughout the Catalog, Cart and Checkout.
If you use NorPrice for Actinic / Sellerdeck V11 and update Actinic / Sellerdeck to V11.0.4 or V11.0.5, you will need to unzip the attached file into your Site folder(s) after the Actinic update.