Dembski's at it again, he collaborated on a list of ten questions to ask your teachers about intelligent design. Instead of going through them one by one (PZ does it already), instead I want to focus on the elephant in the room, that is we have no evidence of a designer working in nature.
There's a aphorism which I'm sure you're all aware of: "When you hear hoofbeats, think horses, not zebras." But what if we're missing the obvious? Why don't we ever think unicorns? After all unicorns would make the same sound as horses and zebras. So consider two people in a forest hearing hoofbeats. One turns to the other and says "listen, hoofbeats. I wonder if it's horse or zebra?" The other responds "It's neither, that's a unicorn."
As they rush to the clearing to see, they get there too late. They can only see the backs of the beasts in the distance. Upon inspection of the hoofprints, the first person points out that the type of hoofprint must belong to a horse as zebra prints are slightly different. The other person maintains his unicorn position. "Well of course they are going to look like horseprints, those are the prints a unicorn makes."
As luck would have it, a hair from one of the beasts' tails had fallen off in the rush. The first person having some Equine knowledge looks at the hair and concludes that it's definitely a horse. Again the other person says "Unicorn hair would have the same appearance as horse hair." Still not able to convince the unicorn believer that it's just a horse, he sends the hair away for DNA testing.
A few weeks later, the results come back. And to no-one's surprise, it's an identical match to horse DNA. Conclusive? No, the other person again is defiant. "Of course it would look like horse DNA, you're forgetting homology. Horses and unicorns are almost identical, so of course the DNA test would come back this way." No matter what evidence the first person could point to, the second person could always come up as a reason to why it was unicorn.
Yet despite the insistence of the Unicorn believer, why don't we ever think unicorns when we hear hoofbeats? Well because there's no actual evidence that there are such things as unicorns. Yet when ID advocates try to infer design, they are neglecting the huge problem in their argument - that there's no evidence of a designer. So while ID advocates go on and on about what looks designed, until they show that there's an actual designer in nature, they have no more an argument than someone hearing hoofbeats does for the existence of unicorns.