If you want the natural scrolling feature of newer OSX-versions on Ubuntu, there’s absolutely no reason to install additional apps to take care of that… Simply create a config-file to reverse the scrolling direction and update xmodmap using that file;
Create a new file called .Xmodmap in your Home directory, paste this simple line and save it.
pointer = 1 2 3 5 4 6 7 8 9 10 11 12
To make make the mod effective right away, run
…and violà – you have natural scrolling :)
The next time you log in, it will ask you if you want to load the config file, click yes and “don’t ask again” and never pay attention to this again. Hopefully they will add this to future builds of Ubuntu, to make it an option in the standard drivers – if not default.