In researching the question Which is correct, “buck naked” or “butt naked”?, I found a very thorough examination of this question at Language Log that I linked to in a comment under the OP. I feel like the information there deserves to be formatted as an answer to the question, but I'm not sure the best way to do that in a situation like this. I could:
Keep it as a link in a comment (keeps good info kind of obscure).
Cut & paste the whole Language Log post (excessive and possible copyright issues).
Just post a link to the discussion as an answer (possibly rude, doesn't really incorporate good info into this site).
Summarize and link (probably best, but seems redundant and awkward when the original post is concise, well written, well-researched and should really be read in its entirety).
Any other suggestions?