It would be helpful to be able to opt to always save manual orders to Customer Addresses, instead of having to remember to check the box every time.
It would also be nice to be able to opt to automatically save any non-manual orders to Customer Addresses.
Since there is a handy search function for Customer Addresses when creating a manual order, this would make it very easy to always have an address "on file" in one place without having to search between Shipping Easy, the store(s) database(s), Paypal, and our e-mail archive.