Re: Makes for a good cleaning fluid.
Yup, excellent for floor cleaning.
Also totally true about the gloves comment. If you stick you hand in it and keep it there then you're in trouble, but you can actually "swish" (for want of a better word) your hand through LN2 without issue as long as you're quick and keep it moving. As noted the vapour that forms around your hand insulates it from the liquid and you're fine.
But if you're wearing gloves and it splashes on them, they absorb it and freeze to your skin if you're unlucky. The only cryo-burns I ever had during my PhD years (using LN2 and LHe on a daily basis) were from gloves until I learned that lesson.
Great stuff for getting kids interested in science though. We did a schoolkid lecture every year with all the usual tricks (hammering nails into wood with a banana, shattering rubber tubes and roses, making a metal ball shrink and pass through a ring that it had been sat on at room temperature plus the standard superconducting magnet stuff).
Oh and it's great on hot summer days for making instant ice pops, and of course keeping the place nice and cool with the aid of a small fan.
Fond memories indeed...