I think it would be great if there were a page dedicated to manual orders (not a pop up window).
We have a small gift shop and have customers that like to ship the products they purchase. Instead of writing their info down, I'd like to set them at a computer and have them type in the address themselves. The current "pop-up window" allows them to see and potentially edit all of our existing orders.
Even better would be the ability to have a separate login that only allows manual order entry.