Flash Paper
Mix 5 parts nitric acid, 4 parts sulfuric acid. Place a piece of toilet paper on a dish. Soak for 10 minutes. Allow to dry.
It is stronger than normal tissue, and has a gel-like texture.
When lit, it burns before hitting the ground.
Note:
You are making nitrocellulose, also known as "celluloid." Basically, sugars, such as the cellulose that makes up paper, are appended with hydroxyl (OH) groups. The nitric-sulfuric acid mixture is a nitrating agent, converting the hydroxyl groups to nitrate esters (ONO2). This nitrocellulose now basically contains its own oxidizing agent. The same reaction occurs to make nitroglycerine from glycerol.
What I'm not going to say is how or where to get nitric acid
Flash paper is used by magicians for their pyrotechnic effects and is very dangerous, If someone uses it to, say, shoot flames out his nose, well, he's just an idiot. Also, nitric acid is extremely toxic.
Flash paper is probably best purchased over the internet along with flash paper shooters.
You can make flash shooters with kitchen match heads too, and its much safer!
Pop Rocks
Mix iodine crystals in ammonia until the iodine crystals well. Drain. Wrap in cig papers.