Watch this science video tutorial from Nurd Rage on how to make flaming jelly from antacid, vinegar, and alcohol. This is useful for camping, pyrotechnics, and just setting stuff on fire in general.
First, get one of those antacids that have equal or greater than 1000mg of calcium carbonate per tablet. Crush the tablets into a powder. Then simply add 10mL of vinegar and stir. Let the mixture dry out until it becomes less than half of its original volume. But keep it as a liquid slurry, if it dries out too much add some water. Once you have your slurry add it to rubbing alcohol in small amounts and stir until it becomes a jelly. Then scoop it out and light it up!
Exactly how much slurry you need depends on the particular antacid you choose. So just experiment until you get the right mixture. If you add too much slurry the mixture will liquify again. So trial and error are your best bets.
The tablets must have more than 1000mg of calcium carbonate, if its less then the reaction probably won't work.
Use 99% rubbing alcohol (isopropanol) because it is cheap and anyone can get it. Lesser percentages might work, but who knows.
Ethanol (95%) works better but not everyone can get their hands on that.
What's happening is that you're creating calcium acetate from the calcium carbonate in the antacid and the acetic acid in the vinegar. Calcium acetate causes alcohols to gel. So with these two substances you can get rubbing alcohol to gel. But because antacid has sugars and fillers the gel won't be as good as gel made from pure calcium acetate. If you can get your hands on pure calcium acetate then go with that instead.
Don't play with fire if you don't know what you're doing.
Brought to you by one of WonderHowTo's favorite scientists NurdRage.