This is really awesome, thank you! I cropped a bit and made 9 wallpapers out of it for Windows to cycle through; and I enjoy i even more that way.
There are some issues you may want to fix if you ever go and improve on this: * Zoro's eye, but someone already mentioned it. * Chopper and Nami have careless colouring that go over the line a lot. (Maybe others too, but I noticed it for them.) * Choppers upper 3 rows of pixels are messed up with a black bar. * Usopps line-art on his arm could use perfecting. * All images have different heights & widths, so I had to crop them to the smallest common denominator. This is not an issue for your image (except for people with really sharp eyes), but if people want to do what I did they'll have to crop more than they'll want to. (I'd offer up my croppings and intermediary work to the masses but I have no clue about your license and such.)
Mind you, I really love this work, and will enjoy it for a long time to come!