I'm currently using a MacBook Pro (5,5) with Ubuntu 11.04. Everything works great except palm detection with the Synaptics driver. If I use the "multitouch" driver, palm detection works great. In the past this is what I've done but the multitouch driver won't turn off the trackpad while typing and, given the size of the trackpad, it's tough to avoid. ;)
I've been playing with the various settings for a while (both through the GUI and by adding options to my Xorg setup) but nothing seems to change the behavior of the trackpad. I can see that my settings are taking effect through synclient, it just doesn't seem to change anything.
Has anyone managed to get this working? I'm starting to think the problem is specific to Ubuntu, there are many pages on the internet that claim to have this working.