I'm am new to this and just reading so forgive me if I get anything here slightly off but I have been making some observations.
It seems to me that the whole cloaking (is it ethical or unethical) debate is somewhat silly.
Let's say the following...
I set up a site that I want to be my main site. Then I set up multiple sites (throwaway) to direct traffic to that site.
So what if I design the throwaway sites so some stupid spider sees a bunch of what it wants and says "wow this site (the cloaked one) is amazing! Woohoo I'm going to list it at the top of the ranks for the content rich keywords."
To me to say that it is unethical to do this is kind of like saying news releases that aren't really news are unethical or guerrilla marketing is unethical.
I get a product in front of people who want it. If I put up a bunch of neon signs in front of my store is that unethical? If I set up my grocery store so that you have to travel through the whole store to get a gallon of milk is that unethical. If my website directs you in every way i can think of to buy something you really probably don't need...Is that unethical? If I choose soothing colors for the store I run so you will feel at ease shopping there and spend more money, is that unethical?
I say all of those are pure analytical business decisions.
I say cloaking is straight up a matter of analyzing a risk to reward ratio.
I decide whether it's worth paying $7 or $8 for a throw away domain that i will generate a ton of content rich / albeit spammy template based mini sites that spiders eat up but show my user something different.
I say it's a matter of whether I want to risk throwing away / investing some time to get new customers. I don't hurt anyone as far as i can see and fail to see where ethics is involved at all.
I have seen some people saying that cloaking is lying about the content of your site.
I disagree. You are just presenting the content of your site in such a way that the spiders will like what they see and showing your customers the same basic thing but in a way they like to see it.
What I write for the spiders should accuratelty reflect the actual content of my site and my site should do it's job and sell whatever I am advertising to the customer.
If my site shows tons of flash animations of blue widgets in a green forest then my content for search spiders should so reflect that and my intended audience should be happy that they have found my very user friendly easy to look at site.
Really it's not my problem if the search engine designers didn't hope to get the info I presented in the manner in which I presented it. Their recourse is to ban my site and I have analyzed that as the possible risk before I cloaked in the first place.
I should in turn be prepared in case they decide to ban my site.
End of story no ethics involved.
That's my take on this thing.