Siri has made it’s way onto iPad 3 thanks to iOS 6 and it’s actually one of the best reasons to upgrade for 3rd gen iPad owners. Though you should see the option to enable Siri during the first reboot and basic setup after updating to iOS 6 or getting a brand new iPad, if you somehow skipped it or didn’t see that option.
How To Enable Siri
Open Settings and tap “General”
Find “Siri” and flip the switch to “ON”, make any changes to Voice Feedback, Language, and your identity as necessary
Close out of Settings and Siri is ready to go
With Siri enabled, hold down the Home button for about 2 seconds to activate Siri and start asking questions, request information, and even launch apps. The voice recognition aspect is just like Dictation in iOS and OS X, but with the responses it’s obvious Siri has undergone some major improvements behind the scenes, and the ability to answer even some obscure questions has dramatically improved.