Thanks to Solveig Haugland, who has posted about this Fantastic OpenOffice.org Writer extension for searching and replacing carriage returns (two in a row, etc.) with regular expressions, plus much much more.
I’ve installed it, and my days of copying chunks of text to my text editor to do this is over. (I used to cut and paste to text editor as it was faster and easier for me than the regular expressions route as I don’t use regular expressions often and had to keep looking them up).
I suggest you head over to Solveig’s most excellent website to grab a link to the extension, as well as a brief how-to on using it.