Dock Dividers is a freeware (set) of apps for Mac OS X that allows you to place dividers between groups of applications in your dock. And don't worry, there are both vertical and horizontal dividers, (for side-mounted docks). This can be helpful for productivity if you use the dock alone to launch your apps, and also provides a visual separation between your groups for quick reference. It might not save you a click, but milliseconds rather. There is a similar, previously released freeware that offers a couple of different styles to choose from.
You might notice once you download the Dock Dividers that it contains a group of files with an “.app” file extension. Well, in order to get an icon into the dock, it needs to be an application icon. The reason there are more than one in the download is because you can't place an application in the dock more than once. Right about now you might be asking yourself about memory. Well, I tried that and not only are these apps tiny, you can't even launch them. If you click on one of the dividers, Finder will attempt to launch the app, quickly learns that it isn't really a launchable application, and does nothing. (self quits).