Another reason to jail-break your iPhone 4: You can get Siri
Fiddly, but possible
Apple withheld Siri from iPhone 4 as a straightforward ploy to get people to fork out another £499 for its new iPhone. But there's no reason Siri can't run on the 4 – and you can get it on there by jail-breaking your phone .
Siri ran perfectly well as an app on 3GS too before Apple yanked it from the iTunes store when it bought the voice recognition company out.
Okay, to get the talking wonder assistant, you need to jailbreak a 4S as well and it seems a lot trickier getting the copied app to connect with Apple's servers than it does just importing the Siri interface over. But Irish developer Steven Troughton-Smith managed it and in a filmed test  it works just as few milliseconds slower than it does on the 4S. ®