Get the Android KitKat launcher now
For me, though, the most desirable aspect of KitKat is the refined look of the home screen launcher. It's also the fastest way to deceive people into believing you have the real deal.
So how do you get it? The first step is to head over to this thread on the XDA Developers Forum. The top post includes a set of instructions and a download link for a zip archive containing three APK files that need to be installed in a particular order.
Now, advanced users who are already comfortable opening zip archives on their phone and managing files can do all of this downloading and installing directly on their Android phone. But in general, I recommend downloading the zip archive to your computer first, decompressing it, and placing the files somewhere you can access easily. To get them on your phone, email each file individually (to limit the possibility of file size limitations) to an email account you can access from the phone. Alternately, you can send them to Dropbox or Google Drive and then download them back down to your phone.
But before you proceed with installing them, make sure your phone is setup to work with files from sources other than Google. To do this, dive into your phone settings, select Security, and then with any luck you should see an option to accept files from "unknown sources." Make sure the box is checked and then back out to your home screen.
You'll also need to make sure you're comfortable with the worst case scenario: a factory reset. Members of the XDA Forum have reported mostly successful results using devices running Android 4.2 or later. Anything earlier is iffy. My Galaxy Note II running Android 4.1 was a rare exception, but even then, features such as Google Now voice commands did not work properly. This is a "use at your own risk" procedure, so make sure your photos, videos, data and settings are backed up before attempting this.
Once the files are accessible from your phone, via email or whatever method you chose, select the PreBuiltGMScore APK file first. You may be given a choice of how to install the APK. I went with the Package Installer, but other options may be just as viable. It may also warn you that you are replacing an existing file -- that's fine. Once installed, simply hit Done and move on to the next file, which in this case is the Velvet APK. Rinse and repeat, and finally move on to the GoogleHome APK file. At the end of installing that one, however, you'll want to hit Open instead of Done. Doing so will usher you into clean, slick world of the KitKat launcher (or at least the walk-through introducing it).
As your first order of business, I suggest a tap and hold on the home screen, which will bring up options for changing the wallpaper, installing home screen widgets, and configuring your Google Now experience. If nothing else, choosing from the new wallpapers will help complete the KitKat transformation.
And that's all there is to it. Thanks to the folks at Lifehacker for originally posting this tip.