Use multiple phone numbers from different countries

Is it possible to order multiple phone numbers from different countries?  I can see in the pricing pages obvious options for adding additional numbers in different area codes in the US for example, but the specific use-case we are looking for is:

- Normally making calls from Australia, but occasionally, the US, South Africa, Canada and Europe
- Need an Australian mobile (+61 4xx) number, but also US and New Zealand numbers ideally
- The ability to add additional European numbers in future would be very useful