My first hint: very ugly, but offered here in the hope that something more beautiful will come of it.
MacOS X's Finder creates these rather strange .textClipping files when you drag text into one of its windows. As far as I can make out, only Finder can read them, either in its Inspector or in a Finder window that pops up when you click on the .textClipping file. I guess they're a legacy from Classic Mac, where presumably there are other apps that can read them (SimpleText?). You can't copy and paste their contents from Finder, so my task was to find a way of extracting their content into TextEdit.
Read the rest of the article for the workaround solution...
The trick is that the text is concealed (from normal MacOS X apps and command line utilities) in a resource fork. As well as the plain text, there's some binary junk in there too. So here's my quick and dirty command line fix. Open a Terminal and type:
% cd directory/with/clipping/Wow. This is ugly in at least a couple of ways. First, you shouldn't have to redirect the file into strings (the utility that strips out the binary junk); strings should just take the name of the file as a parameter. But Darwin strings complains that "it is not an object file". Duh!
% strings < Some.textClipping/rsrc > /tmp/xxx && open -e /tmp/xxx
Mac OS X Hints
http://hints.macworld.com/article.php?story=20020401090954295