What is the the Ion Productions XM42? It's a flame-thrower. Able to shoot ropes of fire 25 feet, it is, according to Ion, "the first commercially available handheld flamethrower." Do we think this is a good idea? Ummm, maybe? How is this different from the ones used in war, zombie movies, and the narrow, Nazi-filled corridors of "Wolfenstein"? It doesn't require a backpack full of fuel. Instead, there's a 1-liter tank from which compressed gas is sprayed. Safety-wise there's a valve to prevent dangerous flare-ups, and the XM42 can only fire for five seconds per trigger pull—presumably to prevent crazy people from doing too much damage.
While large, weaponized flamethrowers are forbidden under government law, no such restrictions apply for the XM42. The only caveats are for California, which requires users to obtain a license, and Maryland, in which they're illegal. If you're a resident of the other 48 states, Ion Productions suggests using the XM42 to torch weeds, melt snow, or theatrically light bonfires—seriously. $699; ion-productions.com