So, my recent drink of choice is also Robert Scoble's.  I found it to be one of a very small number of diet drinks that I can stand.  Among them are Diet Dr. Pepper and Diet Dr. B (a knock-off).  I find Diet Mug Root Beer to taste almost exactly the same as the regular version.

Robert, just don't leave it in the freezer and forget about it.  I wanted a cold one and the cans we're cold yet, so I thought a little freezer time would speed things up.  So, I forgot about it.  It was a mess.  It was pretty cool though.