Found this just looking around on the net. The article is dated Jan 23 2012.

If it's not allowed Mods, please delete it.

How To Install Siri On The iPad 2 [Video] | Cult of Mac

saw tht long tym ago ... BUT u need iphone 4s! also its authentication keys are required every 24 hrs!

thanx 4 sharing.

Seems like a lot of work for very little payoff.

at least its legal

And you don't NEED an iPhone 4s there are a bunch of Siri proxy servers out there both free and paid.

Originally Posted by AFAngryWarrior

And you don't NEED an iPhone 4s there are a bunch of Siri proxy servers out there both free and paid.

Using authentication keys from a device which you do not own is not to be encouraged on the site. At best a very grey area, and at worst in the same bucket as piracy.
If you have your own 4S, knock yourself out with your own Siri Proxy using your own Authentication Keys, but no promotion of free or paid proxy services on iPadForums please.

I can confirm that Siriport works on my iPad2 although there are caveats.

First, you're installing an application and "certificate" written from an untrusted Russian source.

Second, getting authenticated can take days (honestly) due to the load on their servers.

Lastly, it's rather limited as the only way to invoke "Siri" is with a long press of the iPad's home button. There's no microphone key on the iPad's keyboard to use for dictation and some applications simply don't work properly. When Siri "finds" location based questions, you're unable to select from the screen. (i.e. "Show me the closest Pizza places" Siri will respond with, "I've found thirteen pizza restaurants, 11 are fairly close to you:" It will display the names and distances, but you don't have the ability to select one from the screen as I can with my 4S)

It does work without the proxy hassles as long as you're aware of the limitations and risks.

Probably best to wait, but I like to push things just a bit. YMMV.