Siri can help with lots of things, but keeping you safe on a dimly lit street isn't one of them. That's why a few savvy inventors from Baton Rouge, La., have created a souped-up case for the iPhone 4 and 4S that pulls double-duty as a bad-guy-zapping stun gun. Here's what you should know about the Yellow Jacket case:

Why put a taser on an iPhone?
Yellow Jacket co-founder Seth Froom says he came up with the idea after being robbed at gunpoint in his home. (Watch an unsettling re-enactment video below.) Froom says he was frustrated that even the guns he had in the house couldn't protect him, as they were out of reach during the break-in, and resolved to come up with a defensive weapon that would be on his person at all times. Well, says Alex Cocilova at PC World, the Yellow Jacket's creators "made a pretty safe assumption" that most people who are about to be mugged are probably already thumbing through their iPhones. 

How does it work?
The stun gun — which looks like many run-of-the-mill iPhone cases, only thicker — delivers a 650,000-volt zap of electricity, and has its own built-in battery. The electric charge is enough to bring down a "fully grown, aggressive, adult male," says Froom. Unlike regular stun guns, which can take several seconds to locate and use, the Yellow Jacket is "easily deployable with one hand" and ready to zap would-be attackers in less than two seconds. Not only does it "protect your ass," says Mike Elgan at Cult of Mac, but thanks to the extra battery, it gives your iPhone an extra 20 hours of battery life in between charges.

Hold on. What if I accidentally zap myself?
Just like a gun, Yellow Jacket has a safety switch to keep the taser from going off unintentionally, and its electrodes are covered by a cap that must be rotated off before the stun gun can be used. These  precautionary mechanisms should "prevent unintentional shocks from occurring," say Yellow Jacket's creators. Look, "I do see a lot of mishaps and drunk bar tricks happening," says PC World's Cocilova, but I also "see a lot of good coming from a device like this."

Where can I get one?
The Yellow Jacket is being pitched on fundraising site, and will be available in three colors: Black, white, and pink. The taser case will eventually retail for $125, but right now, the price tag is $85. Interested parties are advised to check with local law enforcement for state restrictions beforehand. And fret not, non-iPhone owners — Yellow Jacket creators say an Android version is on the way.

Sources: Cult of MacMashablePC WorldWeb Pro News