With one machine on Lion and another on Snow Leopard, I was going crazy. (But not crazy enough to revert the Lion machine to legacy scrolling.) This free app does the trick.
I have been playing with Scroll Reverser for the last couple of weeks. I think I will give it a pass since scrolling down a page is a lot more common than scrolling up the page, and in vanilla Snow Leopard, to scroll down I <i>flex</i> my finger on my scroll wheel, which is an easier movement to repeat over and over again than <i>extending</i> my finger.<p>I sometimes use a friend's iPad, but it is easier for me to keep alert enough to remember the difference between the way the iPad scrolls and the way vanilla Snow Leopard scrolls than to give up the ease of flexing rather than extending as described in the previous paragraph. The trade-off might go the other way if I was using the MacBook's TrackPad rather than an external mouse with a scroll wheel.<p>ADDED. In other words, if you use an external mouse with a <i>scroll wheel</i> instead of an Apple TrackPad, it is more likely than not that you do not want Scroll Reverser.
This is nice. I've stuck with Lion's default setting in order to see if I liked it more eventually and I do, except when I use another computer and try to scroll the same way.<p>This at least addresses the issue for the other Mac in my home that is stuck on Snow Leopard.
I use this, and on my Windows machines, I use this:<p><a href="http://www.autohotkey.com/" rel="nofollow">http://www.autohotkey.com/</a><p>With this script:<p>WheelDown::WheelUp<p>WheelUp::WheelDown
This reminds about me when games started shipping with non-inverted mouse movement. I'm okay with Lion's new scrolling as they don't ever start disabling "normal" scrolling.