Nanacast supports multiple currencies, although you can only have one currency per offer. If you want to offer a product/membership in more than one currency, you could mirror the offer and edit the currency on the Edit Pricing & Delivery page of your offer. The mirror function allow you to maintain the content of an offer in a single instance, but create multiple instances for different pricing strategies, etc.
The real issue is whether or not your payment processor or merchant account/payment gateway supports the currencies that you select. If, in Nanacast, you select a currency that your payment processor or gateway does not support, it will ignore the currency that you've designated and default to USD.
Additional Keywords: Currency, Multiple Currency