USES of Liquid Nitrogen according to Wiki
-in cryogenics

-the immersion freezing and transportation of food products
-the cryopreservation of blood, reproductive cells (sperm and egg), and other biological samples and materials

-as a coolant for overclocking a central processing unit, and other computer hardware.

-as a method of freezing water pipes in order to work on them in situations where a valve is not available to block water flow to the work area.

-in the process of promession, a way to dispose of the dead.

-cooling a high-temperature superconductor to a temperature sufficient to achieve superconductivity.

-the cryonic preservation of humans and pets in the hope of future reanimation.

-as a coolant for vacuum pump traps and in controlled-evaporation processes in chemistry.

-as a coolant to increase the sensitivity of infrared homing seeker heads of missiles such as the Strela 3.

-as a coolant to temporarily "shrink" mechanical components during machine assembly and allow improved interference fits.