01/06/2012 03:35 pm ET Updated Dec 06, 2017

Spire: Install Siri On iPhone 4, iPhone 3GS, iPad And Other iOS 5 Devices Legally (VIDEO)

Scroll down for how-to video.

Ever since the release of the iPhone 4S, hackers have been diligently working to port Siri -- the voice-activated personal assistant app exclusive to the new phone -- to other iOS devices.

Now, Grant Paul (aka chpwn) and Ryan Petrich have released "Spire," a tool for installing Siri on any device running iOS 5. Unfortunately, while Spire will let users install Siri directly -- and legally -- from Apple, getting the software to successfully communicate with Siri's servers is another task entirely.

Writing on his blog, Paul admits Spire is "not a complete solution" and explains the trouble with getting iOS devices other than the iPhone 4S to run Siri properly:

"Apple still requires authorization to use Siri, so information from an iPhone 4S is still required. To insert this information, Spire allows you to enter your own proxy server address. I've put up a list of my ideas on how you might get access to a proxy; hopefully you can figure something out."

Paul suggests a number of possible solutions, including snagging some authentication tokens from a friend who has an iPhone 4S and is willing to share, or perhaps paying for them on some sort of yet-to-be established marketplace for trading access tokens.

As for any possibility that the iPhone hacking community may circumvent the Apple firewall in the future, Paul says that's "very likely impossible."

Writing for TechCrunch, Sarah Perez notes that this is not the kind of statement to be taken lightly when coming from an iPhone hacker.

"Remember, hackers don't often throw around words like 'impossible' too often," Perez wrote. "Clearly, Apple has some heavy-duty security in place for managing Siri requests."

So, while Spire may help users install the software, they're essentially left to their own devices when it comes to making Siri work.

For the more adventurous iPhone users out there, Spire is currently available in the underground app store, Cydia.

Of course, Cydia can only be accessed from jailbroken devices. Luckily, the iPhone Dev-Team recently released an untethered jailbreak solution for devices running iOS 5. (Click here to find out more about that.)

On the other hand, Google is reportedly working on its own Siri competitor named "Majel."

According to eWeek, Google engineers working on the project are adding natural language processing enhancements to the company's existing voice search application, which has been available on iPhones and Android devices since 2008.

But CNET speculates Majel could end up being much more than a Siri knockoff, especially considering Siri actually uses Google as its default search engine.

If you're interested in learning how to install Spire on your older-generation iPhone, check out the video (below), featuring step-by-step instructions, courtesy of Revolvrr.