unfill/defill

[Chris]

I sometimes need to take a few paragraphs (2-20) from a text file created 
in Emacs using auto-fill and put them into another application. All 
paragraphs are separated by a blank line. What is the simplest way to 
"unfill" or "defill" these paragraphs so that each paragraph is one long 
line? Ideally I could highlight the whole region with the paragraphs I need 
and unfill them all at once, but retain a blank line between each one...