Complexity ⇏ Design
For those who haven't been paying attention to the idea of intelligent design, here is my understanding of it. There are many instances where living creatures have some adaptation or anatomical feature, typically described as "complex", for which we don't know the exact evolutionary pathways. Some people think that this information is somehow fundamentally unknowable. And as such they think the presence of a designer is required to explain the existence of complexity in living things.
There is plenty wrong with this, and any serious search on the web will reveal many eloquent rebuttals. pandasthumb is an excellent starting point.
However I have not yet heard from any designers as to their views on the assumed causal relationship between complexity and design, because frankly it is counter to everything I know about the subject of design. Speaking as a designer of software, the values that we strive to attain in design are most definitely not complexity.
In my experience, complexity is typically what you get when you don't design something, or at least design it badly. Instead, what we strive for is to make things "as simple as possible, but no simpler", as attributed to Einstein.
[Aside: what Einstein actually said was "The supreme goal of all theory is to make the irreducible basic elements as simple and as few as possible without having to surrender the adequate representation of a single datum of experience". The attributed quote seems to have been an oversimplification...]
Anyway, good design always follows the rule of "simple as possible, but no simpler". In some way I think certain ID followers grasp this. I believe the phrase "irreducible complexity" is used to indicate that a given anatomical feature is as simple as it can possibly be, while still performing the same task. Others can better address this as relates to evolution. But within the current set of living things you certainly don't have to look far for examples of reducible complexity:
Evil Genius: God isn't interested in technology. He knows nothing of the potential of the microchip or the silicon revolution. Look how he spends his time: forty-three species of parrots! Nipples for men! -- Time Bandits
So if there is a designer at work in the creation of living things, he doesn't always do a great job, at least from the perspective of the "as simple as possible" maxim. Fair enough, we probably don't always understand the need for every anatomical anomaly that nature has thrown at us, but this doesn't mean they are all absolutely necessary either. It's hard to imagine what the hypothetical designer of humans was thinking when they added the appendix, for example. A Friday afternoon rush job maybe?
On the other hand there are certainly many examples of such jaw-dropping elegance and simplicity and, yes, beauty in nature. For one thing, how about the process of evolution itself? If you're going to look for evidence of an intelligent designer, why not start there?