convert currency

Hi there,
I'm wondering how to add a currency converter, so users will be able to convert the price to the equivalent to their currencies. The main currency is the Canadian Dollar. However, I will be configured it using paypal. I do not want users to see the converted currencies throughout the checkout process. I only want the Canadian currency to be showing in checkout.

thanks,

Thanks Nicolas, this solves my issue during the checkout process. However, in the product page they still can see the two currencies ,the main and the converted . When I switch the hikashope currency switcher to the desire currency I still see the tow currencies. For example :

Main currency : CAD

Product :RAM
Price : ( CAD 20 )

After switching to US :
price : ( CAD 20 ) ( US 19.30 ) I want to hide the CAD , and only display US after switching.

I found it , I have just to set the option in Associated category listing " show the original price " to No. Solved.
Thanks