An interesting project has cropped up for the HTC One X on XDA developers and they have made an Ubuntu Touch build available for download. We would say that the project is still very much in Alpha stage as a lot of components do not work. That said, the developer community has been to boot into system.
We will have to wait for sometime so that HTC One X community is able to make it good enough for everyday use and for that, we will need them make telephony, UI, Wi-Fi and camera to work properly and reliably. Find download and installation information here.