SmartDupe is bash script which replaces file Duplicates in a given path by Hard links to free space on your Hard Drive.
Great script, works well on Mac (Mountain Lion 10.8.2) HFS+ drive. Tested alpha version. There is room to improve, for example - a "Yes to all" option would be good to create all found possible hardlinks in one go - the file size limit behaves strange, as with the default setting 1000 byte 10-100 kByte files were skipped. Lower value (2) worked fine for me. This going to be a great tool for everyone who just want to get the job done without messing around. Thank you all!