OK

This question has been needling at me for some time.  And when The Colbert Report mentioned it the other night, it spurred me into action.  So I Googled it:

http://wiki.answers.com/...

Answer:
No, the ability to breath fire is produced via the lungs and throat. It might be possible to burp fire, though... Anyway, flatulence isn't flammable, even for a dragon.

Read more: http://wiki.answers.com/...

Sadly, dragons cannot rocket themselves into the upper atmosphere on flatulence alone.   I can't tell you how disappointed I am right now...

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