Thanks - I'll add that to the list (I'm tied up another project for the next few days).

Another site suggested this simple AppleScript code:

set sourceFolder to choose folder
tell application "Finder" to set theFiles to files of sourceFolder whose name extension is in {"doc", "docx"} or creator type is "MSWD"
repeat with oneFile in theFiles
do shell script "textutil -convert txt " & quoted form of POSIX path of (oneFile as text)
end repeat

Very elegant - if you're on a Mac.