An intimidating question and one that is problematic due to the assumed nature of the "intelligence's" existence. The entire pretext of a "Maker" ipso facto implies that existence itself is proof of the Maker and neceessarily must be intelligent design.

Notwithstanding this philosopical nay theological arguments, this website appears to contain many useful links:

http://tinpan.fortunecity.com/carpenters/690 (no it's not mine)

and this one is very passionate: http://www.intelligent-design-evidence.com

The strict argument for evidence appears to run as follows - anywhere where a gap in empirical knowledge exists is by default filled with the proposition "Intelligent Design effected this"

For example: the universe began with a big bang - where did the big bang come from - possibly a pre-existing collasped universe - where did this comes from - a big bang ...... ultimately matter existed in the first place from UNKNOWN - therefore gap in knowledge i filled by intelligent design.

The error in scientific conclusion here is that lack of knowledge does not cause the existence of intelligent design it merely retains a gap and hence there is no evidence for direct evidence of intelligent design except by omission and default.

Despite all of this we have to ask the question - even if there is a Maker and He effected Intelligent Design, who then is the Super Intelligent Designer of the Intelligent Designer?

The short answer is no. How ID (Intelligent Design) defines evidence and science is different from how the scientific method defines evidence and science. See http://www.intelligentdesign.org/whatisid.php The Discovery Institute's own definition of ID.

In comparison, there are many resources which define what science and evidence mean by the scientific method. Here is one. There are many others. http://www.visionlearning.com/library/module_viewer.php?mid=45

However, ID proponents argue that ID is correct simply because complex specified information (CSI) cannot self-assemble or spontaneously generate without a designer (for detailed ID arguments see Dembski, an ID proponent and CSI architect). The basic argument would seem to beg the question: Life is too complex to arise without a designer; the designer creates life through a supernatural specific complex assemblage of stuff (that stuff might be information, proteins, amino acids...you get the idea). Or, put another way: Complex organisms are too complex to evolve as is made clear by their complexity (what?). If this seems to be no argument at all...bingo!

This is a very very simplified critique of Dembski and other ID supporters' arguments; however, if you look to information theory (on which Dembski bases his incarnation of CSI), you will find his mathematical formula not to be related to a single concept in information theory. What he seems to be doing is complicating the simple "complexity requires a designer" argument to the point that most of us throw up our hands and say either "I'm not qualified to unpack this" or just to accept it at face value. Or, so would it would seem Dembski and ID supporters hope.

@Awalmo: I don't have enough rep to comment but a thought I'd leave a link to an essay on how information could be created by natural selection explained by Richard Dawkins. Basically the environment culls (some) noise out of the genome and what is left is (some) information on how to survive in that environment. It's a good read and Dawkins is careful to explain the information theory stuff in an accurate but approachable manner. I found it fascinating.

My personal feelings on this matter are thus: Science cannot be used to explain faith, or in some circles, "intelligent design." Science is based on testable, reproducible facts. Anyone that has "faith" cannot give you "faith," cannot hook themselves up to a computer to measure their "faith." I think that in some instances, some scientists have tried to make the point that because there is no measurable evidence to support it, there cannot be a maker, and all of this happened by accident. To fight back, those behind intelligent design say that science is flawed by nature (as it is an outgrowth of human intelligence) and thus is not to be trusted.
Neither opinion (and I do mean OPINION) appeals to me, since science should not try to explain religion (there are other phenomenon that science cannot explain), as someone's faith is a personal thing. If you believe in such things, faith is a gift given from on high, to those who seek after it. By the same token, intelligent design proponents should not try to explain or devalue science. First of all, you cannot argue with the facts. Second of all, trying to argue with facts that are plain to many other people makes you look extremely foolish. What am I trying to say here? I know that there is a God. Do I have any specific, measurable evidence to back that up? Of course not - just a feeling in my heart that I know he is there. Do I "believe" in science? Of course I do - I have a degree in Human biology, and a degree in general chemistry, and am currently in medical school. So I just think that these two completely different entities should remain separate. Like church and state. Just my two cents... ;)

FAQ: Does intelligent design make predictions? Is it testable?

The Short Answer: Yes. Intelligent design theory predicts: 1) that we will find specified complexity in biology. One special easily detectable form of specified complexity is irreducible complexity. We can test design by trying to reverse engineer biological structures to determine if there is an "irreducible core." Intelligent design also makes other predictions, such as 2) rapid appearance of complexity in the fossil record, 3) re-usage of similar parts in different organisms, and 4) function for biological structures. Each of these predictions may be tested--and have been confirmed through testing!