modmyi (that post has most of the icons as of the time I made my theme). Others I made myself using the psd found in the first post of that thread. I also posted my market icon a couple of pages back
I love this icon set and the way I have things set up. There are a couple of other colors of the same type of icons made by H0CKEY over at the modmyi forums (iphone forum, I know) and I'm going to make a couple of different sets for myself, just to change when the mood strikes me.