Created attachment 318448 [details]
Xorg configuration file
I use both Gentoo and OS X on my MacBook; OS X Lion introduced natural scrolling (essentially reversing the direction of scrolling on the touchpad, so it works like scrolling on touchscreens), and I would like to use it in Gentoo, too, since otherwise it's very confusing to switch directions all the time.
I've written an Xorg configuration file that enables this option for Apple touchpads. I put it in /etc/X11/xorg.conf.d/50-synaptics.conf, but ideally I think it should be merged with the relevant section in /usr/share/X11/xorg.conf.d/50-synaptics.conf (provided by x11-drivers/xf86-input-synaptics).
I personally hate this "natural scrolling" behavior and I wouldn't vote for changing from the upstream default.
On the other hand this is easy to configure but would probably make a good note for any wiki about configuring a macbook running gentoo.
I am pretty sure that this won't get merged to upstream. It is such a drastic changes in behaviour and it's personal preference. I also would vote against switching from upstreams defaults.
But you could update the unofficial gentoo wiki (as Gilles suggested):
Natural scrolling is supported by libinput, which is the new default.