The Fire Footbag is pretty much a Hackey Sack made out of Kevlar that you douse with kerosene and then kick around until you've burnt the entire neighborhood down. They're similar to these magic balls (but more kickable), and cost $25.
THIS PRODUCT IS EXTREMELY DANGEROUS USE EXTREME CAUTION!
This product is also extremely fun! You will need white gas, kerosene, or 'tiki torch fuel' to light this bag. Tiki torch fuel is does not burn as hot as most other fuels. Do not use gasoline! Use only a small amount and test it first! Overly soaked bags can be EXTREMELY dangerous since excess burning fuel can stick to clothing and/or skin. Keep your fuel source completely away (100 yards minimum) from your kicking area.
Now I'm all about kicking around a flaming turd, but come on -- 100 yard minimum distance from your fuel source? That's a freaking football field. I'm a pretty wild kicker, but I don't think anyone has accidentally womped the hackey that bad. Why not go the extra mile and include a "Do not play with the Fire Footbag in states that sell gasoline" warning. Oh, and it definitely needs a "Only one flaming sack at a time: under no circumstances should you play wearing loose-legged shorts."
Hit the jump for the VIDEO of a guy doing some pretty cool tricks and dropping the thing a bunch.