mmm hmm, delicious!
you can also order a dewar full of liquid nitrogen from your local gas company. they deliver, although they usually require a deposit on the dewar. the best thing is that by the gallon, the LN2 is cheaper than milk! at about $0.89/gallon, you could get enough LN2 to make enough ice cream for a small army and still have enough to cool off your house, make huge water-vapor clouds, freeze everything you can see (including roses, basketballs, and anything else you might want to shatter into a million pieces), and then fill up some 2-liter bottles and watch them explode (dangerous! loud!)