Putting an iPhone in a case is still not something I'd do or recommend as necessary, but if you must protect your precious, here's a case that claims to protect your touchscreen with a layer of plastic, but also allow you to finger the lcd just the same. It, of course, involves some patent-pending tech which sounds like hocus pocus to me. Here's what Mike Wissman, VP of Ops for Ivyskin, gave me as an explanation.
The case uses a patent pending design called Surface Xylo Wave (SXW)© technology passes ultrasonic waves that pass over the touch screen panel and transfer them to the iPhone's screen without any interferences. When the panel is touched, a portion of the wave is absorbed. This change in the ultrasonic waves registers the position of the touch event and sends this information to the iPhone's screen for processing.
Anyone care to explain that explanation to me?