Abbeytoo -- Haha... Yeah, I know what you mean about cat pee sneaking its way into every conversation. At first there was something amusing about the thrill of the hunt/quest for the perfect product, but then it just became frustrating.
I don't really understand why Consumer Reports or some other publication hasn't compared products, or why no one seems to know what the optimal product is. No matter where you look on the internet, no one agrees on which works. It seems like the problem should be solvable, and that there should be a well known wonder-product... I mean, you just need to figure out the right chemical reactions to neutralize the pee odor. Its 2004; don't we have the technology?!
About Nature's Miracle: Yeah, I agree. (As I'm sure you know

) The problem with biological/enzymatic products is that they won't work if you've already used some other detergent. And even if you haven't already tried all of the cat-pee-odor-removers on the smelly spot, it's likely that your carpet has been cleaned some time in the past, and has a soap residue.
I am somewhat confidant about the Odorcide 210 stuff that I posted a link about. Here's another link with more of a description:
http://www.rhcarpetcleaning.com/en-us/p_15.html
They actually talk about the chemistry of the stuff, which makes it seem less like one of those "Sure, it works" mystery products. I plan to order it.. if it works, I'll let everyone know.
But, I digress
I *did* discover something interesting in my quest, though. I didn't mention it since Jinky asked about getting odor out, not about preventing cats from going there again. Ever heard of Feliway? It's a spray that contains cat facial hormones (the same ones that cats rub on things when they're content). It's supposed to be used to prevent spraying, rather than inappropriate peeing, by calming the cat. My cat doesn't spray, but I thought I'd give it a try anyway. My theory being that cats rub their faces where they sleep or are comfortable, and animals don't want to pee where they sleep.
So: My cat has been peeing on one distinct area of the carpet instead of the litterbox. Starting a few days ago, I tried spraying the Feliway on the area where he pees. I spray the stuff there every morning. Weirdly enough,
it worked. It actually worked! He hasn't peed outside of his litterbox once. The funny thing is that the area does still smell like pee, and if I can smell it, he certainly can. Yet, the hormones apparently signal him not to go there. Now all I need to do is deodorize the area enough that *I* can't smell it, which shouldn't be so difficult a task. I mean, the reason that none of the cleaning products are good enough is that cats have that supersmelling ability, so even if the area smells fine to you, the cat will smell any miniscule urine residue, and pee in that area again. But that's apparently no longer a problem. And hopefully, after he'll become conditioned not to pee in that area so I won't have to spray the area forever.
Hope this info is helpful...
Whew. That was a long post.
-e.