Light your hands on fire for about two minutes.
Obviously, this is about the coolest thing anyone can do.
This instructable is a little crazy, but you should be able to pull it off safely.
One warning: Do not attempt this without extensive experience with fire and acetone.
You should know the chemical properties of acetone and physical properties and behaviors of fire. If you think you know everything, I bet you have not thought of wind, dripping acetone, itching your nose, freaking out, or having a seizure.
To try this, I recommend:
A friend to help you get the gloves on,
a large body of water nearby
a lot of prior experience with fire
Do not do this on a windy day.
Wear long sleeves (soaked in water) that you do not care about.

So many steps might scare you away, but this is very easy.
If it is done correctly, not much can go wrong.

Step 1: Materials:

1 Pair of lined rubber gloves (something that will not let water through)
Several pairs of cheap cotton gloves
Water
Vaseline
Acetone (or other liquid accelerant)
Lighter (candle)
One friend

Step 2: Heatsink Preparations

Completely smear the inside and outside on the rubber gloves with vaseline.
Apply liberally, but wipe off excess. Cover the inside especially.
The vaseline will monitor the speed of the heat transfer because it has to melt before it can effectively transfer heat. (later, the water inside will keep it from melting and burning you)

Step 3: Choose Your Accelerant

Remember, acetone is certainly not your only option; alcohol is another good one, but here's why I chose acetone:

Acetone:
- evaporates quickly, which helps cool and keeps flame farther away from source
- cheap and readily available in most dollar stores as fingernail polish remover
- most impressive flame color (clearly visible even in daytime)
- highest burn (although slightly less safe for that reason)
- lights instantly

Alcohol (91% Isopropyl)
- evaporates less quickly (longer lasting)
- cheap and available at most stores
- somewhat dull flame (nightime only)
- less damaging to gloves
- lights quickly
- significantly less accident-prone

Acetone can also be more nauseating than alcohol.
Acetone is much less stable. Possibly try mixing several different things.

Charcoal fluid
- evaporates and burns slowest (lasts longest)
- gets hotter quickly (not good)
- destroys gloves if given the chance
- less brilliant, short flame

Step 4: Final Preparations

Slip a pair of cotton gloves over the rubber gloves.
Put on the gloves and have a helper fill the inside with cold water (don't just soak it, fill them with water) The more water there is, and the colder it is, the longer it will take to reach an uncomfortable temperature.
Rubber band them as high up on the arm as possible just tight enough to allow blood flow without water leakage.
Apply the acetone (or other accelerant) by pouring it to completely soak the cotton glove.
Keep your arm pointed downwards so that it does not drip onto your arm. Do not get any on your arm or clothing.
Have your friend light it. And film.

Step 5: Have Fun.

DON'T FREAK OUT! You will feel warmth pretty quickly, but it won't get hot enough to harm you for a while.
Don't kill yourself, and don't make punching movements because that would mean putting your arm through fire. Punching is okay if you soaked you long sleeves in water like I told you to. Other than that, you should be good.

Step 6: Emergencies

It should last at least a minute, two if you're lucky.
If you have a sudden compelling need to remove the gloves while they are on fire,
possibly because you forgot water, step on the gloves and pull your hand out.

Step 7: Re-use

After the flame goes out, the cotton gloves will be melted but the rubber gloves should still be fairly intact. If not, you may want to look into other gloves. The water in the glove should be much warmer than before, but not even close to scalding. Peel off the trashed cotton gloves, replace them, and do it again!