I'm so accustomed to having DragThing on my Macs that I forget that it's not part of the OS. It's only when I'm speaking to a group (in person or virtually), show my Mac's screen, and someone pipes up, "What are all those docks on your desktop?" that I'm reminded how much DragThing is ingrained in my computing life.
Although DragThing and I have traveled a long and nearly constant road together, it's not an exclusive relationship. I use LaunchBar to launch applications and open documents that I don't touch often enough to add to a DragThing dock. And unless I really want to clear the decks by hiding other applications, I'll often switch between apps using the Command-Tab keyboard shortcut. But old--and helpful--habits are tough to break. And I am thoroughly accustomed to having DragThing around.