How Yes or No Questions Should be Represented in Forms

This question started out on the Pro Webmasters SE. See: https://webmasters.stackexchange.com/q/8578/1847

I am a web developer. My designer gave me a mock-up of a web form. In it, there are several long winded yes or no questions. Some of which include background information. Here is an example of how it was mocked up:

Some long winded yes or no question?   ◉ Yes   ○ No

As a web developer my intuition tells me that the right way to do a "yes or no" question is with a checkbox and turn the "question" into a statement:

The positive answer to the long winded question ☒

I'm not asking you to tell me how to mark either way up in HTML. I'm interested in if there are "industry" best practices on how yes or no questions should be displayed. Please share any original research, or references to best practices on this matter if you know of any. I have thus far been unable to locate any papers or resources through the usual channels. (read "Google")

UPDATE: I'd like to clarify that this is not an opt-in/out. This is an answer to a question which is completely unrelated to any marketing effort.

Answer

I'd go for the radio buttons. The checkbox is too easily ignored, so a lot of people might answer "no" when they really meant "what, I have to read through all this?"

But instead of just offering "Yes" and "No", use longer labels, e.g.

( ) Yes, I want to become a member of the eat-all-you-can-club right now.

( ) No, I don't want to become a member.