1. International Money Order
2. Wire transfer and/or Western Union
3. Perhaps the ability to add custom methods as there are many more available options.
ON item #1 this realy needs to be separate from Money Order as the requirements are different
item #2 I recently learned that in some countries there is no option outside of PayPal or Credit cards - I have processed an order with Western Union, no issues, for a customer in HK. It isn't a risk if you are dealing with a reputable seller! Also for high value items (over $500) PayPal offers NO protection, if a customer would rather not wait for a check to clear then wire transfer is a good option.
Thanks Graham