One of the big rumors about Lion (10.7) is that scrolling is reversed ... in other words, if you drag up the page moves up - just like iOS.
I thought this would be really funky, but it's actually pretty cool. Try this app:
http://blog.pilotmoon.com/post/4041089648/scroll-reverser-get-in-practice-for-lionit will allow you to reverse scrolling in pure user-mode ... in other words, just throw it in the trash to get rid of it.
The difference between me and most is that I gave up on mice several months ago and have the Apple trackpad instead. I've commented to a few that I'm not certain I like it. But this scroll reverser did it. It behaves like iOS now and feels MUCH more natural when scrolling and your mouse is inside the client viewport. It still feels right to have the scrolling thumb go the other way, but I've not used the thumb since I started using the track pad. Now the metaphor of a document inside a window just feels a lot more right. I really don't know if the experience with a mouse will be the same. In fact, I'll bet it will feel wrong, because the muscle and visual memory of the way things are supposed to be with THAT input device is different.
I actually like the trackpad more tonight because of it. Since I've become quite an iPad centric computester and therefore a touch kindo'guy, the trackpad suddenly feels "right" where it's felt a bit forced for the last while. I dunno, we'll have to see how it feels over the next couple months - and how much more Lion changes up the interface to move towards a more direct touch metaphor. In fact, the effect is so pronounced that it was suddenly wildly obvious how conditioned we've been to the reversed scrolling method. At the beginning, this was really the only way it could be done because you HAD to use the thumb to scroll. But now that we can leave the cursor out in the middle of a page and scroll, the connection of "I move my hand up because I want the page to go up" seems immediately more natural.