Reversed the order comments where sorted at: now it's chronological and that's far more logical ;)
Now that I'm at that point: top posting in an email or usenet message seems to be considered not done. I was a little confused when I saw the strong reactions someone got when he did just that, because I do it most of the time too. I send the original message [email] along as a reminder, but someone stated that, as he wrote the original message, he didn't need that reminder. And when you react on a message, it's logical you do it in chronological order, so someone reading your message doesn't get confused the hell out of him because of reactions on something he didn't even read yet.
I'm reading an article about Spatial Orientation on the computer right now, which is about the human ability to manipulate things in space, based on the knowledge that something doesn't suddenly change size, color, place or number of instances:
Objects in the real world are notoriously coherent and stable. It's extremely difficult to get anything more than a one-to-one relationship between, say, your hand and the $20 bill you're holding. The bill is in your hand and your hand is holding the bill. If you could make that same bill appear in one or more other locations simultaneously (or vice versa with your hand), you'd be a very rich (or very handy) person. Similarly, if that bill starts to change size, shape, color, or location without any outside force acting on it, then you're probably asleep and having a very odd dream.
In the computer world, things tend to be somewhat different sometimes. The autor talks about the old MacOS Finder, with one instance for every directory opened, and the OSX one, that works the same way as windows explorer: you can open multiple windows with the same directory. But what if you close them and open the directory again: where will the window be placed? That kind of inconsistencies is killing the ability of humans to interact with a computer without annoyances, causing all kinds of bad things - from general stress to throwing computers out of the window [you can better do it the other way around]. This is what I like in interface design :)