I’ve found the etomite snippet. It’s called DisplayCode and it’s on the second page of their miscelaneous snippets... http://www.etomite.org/browsesnippets.html?int_page=2&lst_category=10 (I didn’t link directly to the snippet because I don’t think it’s allowed). Ok, that’s not allowed either!
I tried it but got a lot of odd characters that couldn’t be interpreted by the browser and "Warning: Unexpected character in input" warning messages. Also, some characters, like < and >, aren’t encoded into html so the doc is still being interpreted as php (hence the warning messages).