When Apple announced the iPhone 4S the biggest reason to upgrade from the iPhone 4 was without question the new voice-control system Siri.

Siri is exlusive to the iPhone 4S and ever since it was announced developers have been wondering if they can get it to run on the iPhone 4. Steven Troughton-Smith has now managed to get Siri running  on the iPhone 4 after working with 9to5mac.

The interface loads up and it can reconognise and respond to voice-activated commands as intended on the iPhone 4S. However, one problem with the port is that the device can't communicate with Apple's servers so anything that needs to interact with them won't work, such as asking what is the weather like ?

Another problem they've found when running Siri on the iPhone 4 is that its very sluggish. The reason for the slowness is that they need to upgrade the GPU driver, but that hasn't been possible so far.

With time we're sure a perfect port of the Siri application will come to the iPhone 4 and we'll keep you posted on any developments.

Source