[youtube http://www.youtube.com/watch?v=gHQyV9JQzSw]

Following our multiple looks at private Siri ports to unsupported iOS 5 devices with the help of developer Steven Troughton-Smith, Chpwn and Ryan Petrich went public today with a Siri port called Spire.

The port mirrors all the iPhone 4S Siri functionality and works on the jailbroken iPhone 4, iPhone 3GS, third generation iPod touch, fourth generation iPod touch, and first generation iPad. We previously revealed that iPod touch Siri performance is not on par with iPhone Siri performance due to the lower quality microphone system.

Spire is available free on the Cydia jailbroken application market, and the download comes in at approximately 100mb, according to a blog post from Chpwn. The developers recommend that users connect to a Wi-Fi network for downloading, not a standard cellular network, because of the large file size.

A few Siri ports have gone public through jailbreak application markets in the past few weeks, but they were deemed unsafe and illegal by the development community due to its distribution of Apple copyrighted materials.

“Spire uses a new method to obtain the files necessary for Siri, so it doesn’t have the copyright issues encountered by previous attempts,” said Chpwn

Of course, with any port of this kind, there will be a caveat: you have to still gain authorization through your own server and an iPhone 4S. Chpwn explained the issue:

“Until the iPhone 4S is jailbroken, this is the best Siri port,” said Steven Troughton-Smith, “when the iPhone 4S is jailbroken, then we can avoid the proxy server issues.” Spire can be downloaded from this link, if you are on a jailbroken iOS 5 devices.