A lot of people are working on porting Siri to the iPone 4 iPod Touch or iPad, but till now it only is possible to port the GUI of Siri. If you are interested in this, you can folow the how to after the break. “Please note that this is only the GUI ( graphical interface ) of Siri, and there is no actual functionality added to the device. Also please note that there is a possibility that your device will end up in a respiring loop. So do this at your own risk” Check out the Tutorial “including a video” after the break to install the Siri GUI.

You need:

• iPhone 3GS/4 or iPod Touch 3G/4 running iOS 5 jailbroken ( tethered )
• OpenSSH
• MobileTerminal
• Link Identity Editor ( Cydia )
• SFTP client ( like Cyberduck for Mac or iFunBox for Windows )
• iFile ( Cydia )

NOTE: back up your files before doing this

HOW TO:

1. Download and extract this file to your desktop

2. Via SSH browse to /System/Library/PrivateFrameworks/ and copy the AssistantServices.framework folder

3. Load MobileTerminal, and type the following commands

chown -R root:wheel /System/Library/PrivateFrameworks/AssistantServices.framework
chmod -R 755 /System/Library/PrivateFrameworks/AssistantServices.framework
ldid -S /System/Library/PrivateFrameworks/AssistantServices.framework/AssistantServiceses

4. Via iFile go to  SpringBoard.app and find N90AP.plist ( iPhone ) or N81AP.plist ( iPod Touch ) and open them as text and add

<key>720p</key>

<true/>

<key>1080p</key>

<true/>

<key>assistant</key>

<true/>

5. Respring your device

Source [Thanks for the Tutorial FSM]