I recently noticed it as well, the thing is, on some 3gs phones, in sunlight, or strong light, the border is hard to see as it's just about black, but, on some phones like mine unfortunately, it's not nearly as dark, but is a fairly noticable and distracting greenish color, I went to the AT&T store and compared several, some had the greenish, noticable border, while others had a darker one that was all but invisible. The greenish border is definitely annoying as it doesn't blend so well with the edge of the active screen.