Good news for everyone who don’t plan to upgrade to the iphone 4s but want to use the Voice assistant Siri . Several developers have been working to get it working on previous ios devices. And now it has been done , Siri has been ported to iphone 4 and it works pretty well . But it has come drawbacks too ,
first: it lags a bit (note that developers are trying to improve it further)
Second: Siri on iphone 4 can’t connect to apple servers , hence currently you will be only able to do the offline work with siri.
Here is the video of Siri working on Iphone 4