The absolutely best thing about Linux distributions is package management. Especially Debian and derivatives excel at this. Windows and Mac OS plain suck there. Here I will post links to software that I think might be useful for switchers from Linux.
MacGPG is a GnuPG implementation for the Mac. Download the DMGs GnuPG...dmg, GPG_Keychain_Access...zip and GPGPreferences...dmg.
GPGMail is the plugin-hack Í use for Apple Mail to keep private emails private. It enables you to send and receive (and read :>) encrypted email..
Adium supports OTR encryption out of the box but it seems to need a little luck to work, with some contacts it works for me, with others it doesn't. Even though they have exactly the same Adium version, which is a little disappointing.
Disk/File System Encryption
Finally, version 5 of TrueCrypt supports Mac OS. Windows and Linux were supported before so this is the first version that works with all the platforms that I use. Nice.
EncFS is a nice encrypted file system that runs transparently on top of another file system. It depends on MacFUSE. While you're at it, also download MacFusion. I'd recommend using the EncFS version provided by EncFSVault, another great project that uses EncFS to encrypt your home directory and integrates into the login system of Mac OS and thus replaces the built in FileVault. At chuckknowsbest.com you will find a MacFusion plugin for EncFS. And as I didn't really get it first, I'll give you an overview here:
Burning CDs and DVDs
PatchBurn might be interesting for those who have an unsupported drive.
I have to admit that I currently evaluate Exact Audio Copy (EAC) to archive my CD collection. There seems to be no Mac OS application that does the job as thoroughly.
There is Max but from what I heard it lacks the ability to make sure the CD drive doesn't return cached data (which it reads only once of course so subsequent reads to verify the data just return the cached data and the application thinks the data is fine). I also heard that people currently work on that, though.
There are a few (German) articles on AudioHQ that I found useful:
I got a digital SLR so I shoot raw pictures. I use Image Ingester Pro to copy the pictures to a custom folder structure. However, I cannot recommend it any longer as the author decided to no longer distribute a free version. Well, free speech is different from free beer. So one day I'll have to hack a script that does the job for me.
Carbon Copy Cloner, Superduper, Carbon Copy Cloner, Google Earth, Isolator, NeoOffice (soon to be replaced by the real OpenOffice.org), Parallels, Stuffit, VPNClient, VueScan, Winclone
SmartSleep lets you disable SafeSleep or whatever it's called (coming from Linux I call it suspend to disk). I usually have an eye on my battery and I simply prefer the lightning fast suspend to ram (called sleep on the Mac? I'm still a noob.)
NTFS-3G for OS X, finally, after not even Leopard can do it.