It seems some developers took the system dump of the Glass OS and repackaged the critical parts of the OS as APK files. If you're unaware, APK is the file format for all Android apps. After installing three APK files, you'll have a new launcher on your device called Glass Home.
Once you launch Glass Home, you'll see the same UI Glass users see, and you're even able to give the "OK, Glass" command to wake the app and start giving voice commands.
In my testing I was able to Google random stuff, including images of alpacas, and the results were either displayed (in the case of images) or read back to me (non-image queries). I was also able to take a photo, but there's nothing that can be done with it after it's been snapped. I didn't have any luck when it came to getting directions (this feature needs touch-pad interaction to proceed past the warning) or placing any calls, as I don't have an official Glass account to add contacts to.
Of course, when installing APKs from a third-party you need to remain cautious and aware that bad things can happen to your device, or the information on your device. So please download and proceed with caution.
Head on over to the Xenologer Github page for more information about what changes were made to the APKs during the build process, and to grab the APKs should you decide to give it a try.
Again, it's really limited, but it gives you the basic idea of what Glass looks and feels like, just without the looking-like-a-weirdo part. Unless, that is, you decide to strap your phone to your head.
I tested this on a Nexus 4, and my colleague Ed Rhee has confirmed it works on a Note II. Your results will vary, but please leave a comment letting us know if you took the plunge, what device it was on, and your general thoughts.
To remove the Glass apps, you'll need to uninstall all three APKs you downloaded, by going into Settings > Apps > Downloaded.
Note: If this Tutorial and News worked for you (and it should work), please leave a comment below. Thanks.