Alternatives to display radio buttons vertically?

My preference is to display radio buttons vertically per common recommendations, per some research on completion speed, and to take advantage of Fitt's Law.

However, I often get push back with regard to space constraints. While I'm moving ahead with my recommendations, I would like to hear from Devil's Advocates for alternative approaches. Here are a few I came up with, available here: https://docs.google.com/file/d/0B_vkC3_ZQ0bkT3ZKcTNBLWhNNVE/edit

Any suggested alternatives that you think work better than what I have?