We use a ceiling plenum ducted down to the AC units with an grated ceiling in the hot rows to create a vaccuum effect pulling the hot air in, and a 2 foot plenum underfloor with perf tiles in the fronts of the racks to deliver the cold. It's pretty efficient. We don't get a whole lot of spillover, even without damming the rows appart. We did use blanking panels in the racks to stop the convection, but for the most part we've found that air balancing works pretty well. A few small tweaks to the AC settings will give you a fair bit of control as to how much cold air goes where without too much hassle.
We are testing out the chimney idea to separate even more, but so far I'm not loving it. Could be because the damn vendors keep trying to sell me fan controlled chimneys and I keep explaining to them that if you have a vaccuum on one side and a high pressure region on the other and you want air to go from the high pressure zone up to the vaccuum zone, you don't need a fan to do it. The laws of physics and thermodynamics still work. They don't grasp it. I dumb it down to the point of "this sucks hot air out. this blows cold air in. let the air handlers do their job." Nope. Please buy our fancy fans to do what nature will do anyways. Um, no. Bad vendor. No cookie. Stupid ASHRAE.

I have to agree with the need to diversify the terms we use. I may be an "IT Guy" but my speciality is datacenter administration/management. If you need power supplied to a new Blade Chassis or cooling for a new server room, I'm your guy, but good luck if you need me to fix the McAfee EPO agent... That being said, I can't count the number of times I've been stopped by random users and asked to fix their Lotus Notes problems and I still don't know how to breakfix Notes. The term "IT" gives people a false sense that we all do the same job and the reason a department may be huge is so there's lots of people to come to your desk right now and fix it, not because there's a multitude of very specialized tasks that need attending by very differently trained individuals. The catch-all of IT to me shows a distinct lack of understanding in managing the technical talent a company employs.

The Orange Catholic Bible?

That is really amazing. It's one of the best images of the sky I've ever seen that wasn't taken by the Hubble. The only thing that would make it better is if they made it interactive and labelled the stars and constellations. Very cool.

Not true. In order to disbelieve something, you have to believe in the premise that it does not exist. You have no undenyable proof that a thing does not exist, therefore you are believing it does not exist. You may have good evidence which suggests that a thing does not exist, which means that it may be a reasonable leap of faith to believe it does not exist, but it still involves a conviction without proof. Without absolute proof of a negative, the best you can have is a logical assumption, not a logical certainty, and an assumption still takes faith. It's not illogical to say "There's no reason to beleive in god." It is illogical to say "There is no god". The first is true. The second is speculation. Probably good speculation, and I'm not discounting its possibility, but it is true that there is not concrete evidence to support the existance of god, while it is not true that there is concrete evidence to support the non-existance of god. Only probable evidence that supports the non-existance of god.

You're not considering a key fact of the known practices of Scientology. They have been known to violently oppose anyone that openly disagrees with their views and beliefs, and they are also well-known for propaganda and orchestrated operations by its members to influence media. Keep in mind that the protest group, Anonymous, wears masks to protect their identity for fear of CoS members harassing their homes and businesses, as this group has a history of organizing its members to forcefully influence people to either follow them or stay silent.

On a system like Wikipedia that is user-edited, it easily allows for an organized group of a certain belief system to enter their own set of beliefs and through sheer numbers, override the other peers writing to the articles. There simply aren't enough people working to correct misinformation on Wikipedia to constantly correct changes made by the Church of Scientology or any other concerted effort to add propaganda-like entries into articles.

Combine their pentiant for organized propaganda and Wikipedia's vulnerability to misinformation and it just makes sense to ban their posts, not because of a difference in beliefs but in prevention of having a vulnerability exploited.