ExtensionAdder is an OSX ruby script that recursively traverses a folder, adding extensions to approprate files. The script uses the Magic file, but you can extend the behavior by adding your own shell scripts (see the "includes" folder) to grep into files that Magic only classifies as "data".
At this time you have to explicitly state which file types you want to add extensions to.
Download it here
Sandon Jurowski
[email protected]