Nice result. I have a neat method that works with blue and other colors that I would like to share with you. From the bits of technical description, I would say that you're going to understand the process once you try it.
Here's the difference, my method here takes about 6 seconds on average and the edges in fine detail are perfect.(bet that caught your attention) :)
Save the image and I know it's big, so delete this comment when you're done. (or leave it for others it's up to you)
Before starting, Make sure your [b]Layer Window[/b] is open. With photoshop open, [b]press F7[/b] to open and close layer window. If anyone wonders about the name ViaMoi on it, he said I could. :)
[img]http://farm3.static.flickr.com/2004/2096437153_f41da45b84_o.jpg[/img]