Deleting duplicate files

Yes. Try this one:
http://www.apple.com/downloads/macosx/system_disk_utilities/araxisfindduplicatefiles.html

I'm using this:
http://sourceforge.net/projects/ig-scripts/files/rmdupe-1.0.3.sh/download

because I like to run it first in simulation mode and see the result in txt file. To be sure I really want to remove all those files found by application. Then I can use the same txt file for removing the files I want.

make the file executable first:
# chmod u+x rmdupe-1.0.3

then run it like this:
# ./rmdupe-1.0.3 -R --sim /full/path/to/directory > save-the-result-in-this-file.txt

then I go through txt file and keep the lines there with paths to files I really want to delete. also, do search and replace all instances of " sim-removing " with nothing. simply get rid of them.

and the last step would be:
# cat save-the-result-in-this-file.txt | while read line; do rm -f "${line}"; done

-f means force! so be careful with lines you kept in that txt file :)