Apple may not have wanted Siri to work on the iPhone 4, but the virtual assistant is now doing your bidding on the older device, according to iClarified. Siri can now be downloaded through the jailbreak App Store-equivalent Cydia on the iPhone 4.

Apple did not include Siri as a feature of the iOS 5 software upgrade, limiting it exclusively to the iPhone 4S, and it remains debatable whether it was for performance considerations or simply to give current iPhone 4 customers more of a reason to upgrade to the iPhone 4S. However, none of that has stopped jailbreak iOS developers from putting all their efforts into porting the software to the iPhone 4.

It seems that those efforts may finally have borne fruit, as the following video demonstrates:

The port is called “H1Siri” and is available on the “Cydia.be” and “iphone3gsystem.fr/cydia” repositories. While it seems to be working just fine in the demo above, it has been plagued by server issues today, even as the official Siri has exhibited no such problems.

The server issues have led some, including the folks at iDownloadBlog, to speculate that perhaps this is just a port of Siri’s shell and it is still hooked up to Apple’s servers, which won’t allow it to function, thus rendering it useless.

However, given the video demonstration above, it seems likely that the app is using a proxy server like SiriProxy and has been having issues because the latter wasn’t able to keep up with the volume of requests it was pelted with on launch day.

Jailbreaking the iPhone can lead to a voided warranty, and the legality of this hack is also not clear, as the repositories it comes from are known to host illegal apps. The port itself may also contain illegal code.

We are also not sure how secure this is and if it uploads any sensitive data to third-party servers, since the source of the hack is not yet known. Therefore, iPhone 4 users who are itching to try this out should tread with caution.