Dragon Breath
I'm not sure if I should post this or not since I did burn the roof of my mouth and tongue a bit by eating this, but for the adventurous folks there's a place called "Chocolate Chair" that has a dessert called "Dragon Breath":

The puffs taste like Cap'N Crunch... can you see the trail of gas?
If you eat it you can blow out smoke through your nose or through your mouth. I did, however, see a bit of the liquid nitrogen at the bottom of the cup they serve so I advise people to be careful when consuming this.

They also serve ice cream made through liquid nitrogen. We got the strawberry flavored one, and it tasted pretty good:

Farewell!