Here are some comments by Michael Shermer on the distinction between cranes and skyhooks.
Third, as for your comments on ID and questions for evolutionary biologists, I offer this one general response: in his 1996 book, Darwin's Dangerous Idea, the philosopher Daniel Dennett presents a clever metaphor of skyhooks and cranes. Skyhooks are top-down devices to build complex machines when you can't think of how they could be built by ordinary bottom-up cranes. Skyhooks are always snuck in when one cannot figure out what crane did the job and how. IDers, like their creationist brethren before them (and the natural theologians before them all the way back to William Paley and his watchmaker argument), turn to the skyhook because they cannot think of how the crane of evolution did the job.
But how do we decide who is using a skyhook? People like ID advocates, and anti-materialists like me, obviously have to plead guilty. My claim, though, is that even when it is couched in brain-talk, you can still have skyhooks, so long as you have a mentalistic explanation, and you don't explain it in non-mentalistic terms.
I happen to think that Dennett's own Intentional Stance is, in the last analysis, a back-door skyhook.