Synchronize two directories (local or remote)

Found a neat utility called Unison which does two way synchronization between two directories (as opposed to rsync which AFAIK is only one way).  It seems much easier to use than rsync, as well.  You simply use a command like so 'unison /path/to/dir1 /path/to/dir2'.  If you want to sync with a remote directory, you can use ssh in the path specification (ssh://username@foo.org/path/to/dir/).

It works with Linux, Mac, Windows (I found it on MacPorts for the mac).

Customize your app switching behavior

The utility is Witch.

Nice utility to manage sleep vs safe sleep vs hibernate behavior of mac

It's called SmartSleep.  Check it out here.