One of the applications I use the most in OS X is just a script. But it makes my life more pleasant: I could have a hard time without it. I do not like the standard behaviour of the MacOS X trashcan: I would like to selectively empty some files on the Trashcan, and quite often I would like remove files directly without letting them through the trashcan. And Permanently Shred does it. It is very simple. It just executes the UNIX command 'rm' to remove the file (I removed the -P option, since I do not care so much about privacy, so it goes much faster). If you drop a file it gets deleted directly, freeing disk space. And if you open the Trashcan and you drop files there, the files are removed from the Trashcan.
And another simple but nice list of Free and OpenSource software for MacOS X.
