**I have re-written this post after a change in Woocommerce 2.6. Some of the code below is different to how I had it before, so please update your functions files if you have used this previously.
If you are in a country with a currency that is not natively supported by Paypal you might think you can’t use Paypal with Woocommerce. The code below will allow you to convert your order totals to USD before processing via Paypal. I have used this code since 2013, and the below is the latest working version.