We literally gasped when we saw this dish in AB Chao's fantastic Modern + Old = MOLD house tour. We picked up an identical dish while flea marketing in Portland, and scoured the internet for more info on it, to no avail.
All that ended when Flickr user lisamerito commented on the picture in AB Chao's Flickr set, with the goods: the dishes are the Boutonniere collection by Taylor Smith Taylor. Start your eBay search engines -- go!
The rest of the Boutonniere set doesn't have half as much appeal to us as this one dish; the other pieces have a wispy blue flower design on them. Come to think of it, when we picked up our dish, pieces from the rest of the set were nearby. But they looked so different that we thought someone had improvised an arrangement by matching the blue on the inside of the divided dish with the flowers on the others.
The dish's best feature (besides the white on the outside and blue on the inside -- beautiful) is its asymmetrical silhouette. It looks like a little Norse ship. We use ours to keep ginger and garilc handy by the stove.