As skeptical as we are about surrounding the iPhone 4 with potentially signal-reducing aluminum, that's exactly what Artwizz has done with its SeeJacket Alu ($25). Available in six colors, this case comes with three pieces: the metal shell itself, as well as black and white silicone inserts. The phone fits into the insert of your choice; both have nubs that correspond to cutouts on the aluminum frame. When both pieces are together, there are openings…
