We should not be too quick to dismiss Intelligent Design as "unscientific" (The Age, 21/10). At its core, ID claims that the complexity of the natural world absolutely requires an intelligent designer - not just that one is convenient or even plausible. In other words, ID states that it's impossible to explain life without introducing supernatural beings (aliens, ghosts or gods). In much the same way that earlier scholars insisted on the existence of phlogiston or the ether, this proposition is falsifiable and hence (in the Popperian sense) scientific.
So IDers have tried finding impossibility with the mammalian eye. They've tried it with winged flight. They've even tried with consciousness and language. In all cases, naturalistic explanations exist (even if unproven), falsifying the IDers claim to necessity.
Absent an example of something "too complex" - such as a giant black obelisk on the far side of the Moon (Arthur C. Clarke) - I'm comfortable sticking with natural explanations.