Interesting. I really see no reason to run it on your phone at this point, unless you are writing some specific software that runs on Linux. Android is pretty simple for writing software though. Their selling point is that 'it's also a full PC', but so is just about every other phone OS at this point.

What do you think about Ubuntu working on a version for cell phones?

Ubuntu for phones | Ubuntu

Do you think you'd be interested in getting a phone with Ubuntu on it, or do you prefer one of the more major operating systems, such as the iPhone, Android, or Windows Phone?