I would love to try Ubuntu Touch Developer Preview on my Galaxy Nexus GSM, but the walkthrough on the website isn't for OS X.
Thanks for any help you can provide.
I wrote up some instructions that worked for me.:
Pre-requisite: Unlock your phone.
Looks like this installs a version of ClockworkMod Recovery.
The sdcard is referring to the internal storage, not a separate SD card (which the Galaxy Nexus doesn't support anyway).
I successfully installed Ubuntu Touch preview onto a Nexus 10 from my MacBook Pro by running an Ubuntu 12.10 virtual machine in Parallels.
When you plug in the phone or tablet while the Ubuntu VM is running, Parallels will prompt you to connect it to either the Mac or the Ubuntu VM. If this screen doesn't show up (such as if you've hidden it previously by selecting "always open in Mac") you should be able to enable it from the Parallels menu bar, under USB devices.