Julie Witt does! I was pleasantly surprised when Julie of Sewknitful sent me a photo of her wonderful Flower pin that she knit up. Julie then used one of my buttons for the flowers' center and I think it turned out just perfect. The contrast between the blue of the jacket and red of the flower just pops. Julie has posted a link for the pattern on her blog. I think I'll want one of these! Thanks Julie!
I've done various types of mokume gane and have a tutorial on a variation that I call Dichroic Pendants, but learned this style with the 'River channel' from Julie Picarello when she came to Vancouver in November of 2009. I didn't make very many and am honoured this button found a prominent place.