Fork of JPEGDeux found on SourceForge here:
http://sourceforge.net/projects/jpegdeux/
The sourceforge page appears to be dead and doesn’t work on any version of OSX greater than 10.6.
This fork will build and work on OSX 10.7+
A compiled binary for this application can be downloaded here:
http://www.wirelust.com/2013/04/14/jpegdeux-updated-for-osx-10-8/