There is another easier, safer, and potentially less messy to make
carbonizedcarbonated milk, provided you have a carbonation machine such as the Soda Stream Gemini1: Instead of using plain old water, use milk.
I should point out at this juncture, that there is a reason that you are only supposed to put water into carbonation machines, and that is the reason why I used the word "potentially" in the first sentence. The higher the viscosity of the fluid you are trying to carbonate, the more foam you will generate, and thus the more you will spill on your kitchen floor, which is probably already enough of a mess, given that you're the sort of fool who would try to carbonate milk in the first place...
That said, using this method does leave you with carbonated milk, if perhaps not as much of it as you would expect. Where you would ordinarily have a full bottle of carbonated water, you instead have a tenth of a bottle of carbonated milk. (The other nine-tenths are currently pooling frothily on your countertops and floor.)
Now to taste your creation!
(Quick aside first though: remember when you made your first bottle of carbonated water and decided to take a swig of it, to see what it was like? Remember that nasty acidic flavor? Do you know what acid does to milk? Anyway, enough of that, onward!)
Remember what jmc just told us, above? "carbonated milk is disgusting. No one in their right mind would ever drink it"? Well, our pal jmc is right - it turns out that drinking carbonated milk is a little like drinking sour cream. Bubbly, thin, sour cream. Mm, mm good! (Just like mama used to make!)
1Yeah, yeah, yeah, I'll get around to noding that one of these days - in the meantime, Google it.. Or just buy one of the machines - they're that much fun!