iPad has been hacked to enable Phone calling, sms sometime back and the application is now available.
Normally, iPad 3g allows internet connection over 3G, but not calls or SMS. Luckily enough, an iPhone jailbreak tweak called PhoneItiPad brings calling and SMS capabilities on your iPad. The new Tweak allows users to make and receive phone calls, as well as send and receive SMS on iPad and it costs $19.99.
How to Enable Phone calling, sms on iPad
Step 1: Goto System > General > About and note down your Serial Number.
Step 2: Buy PhoneItiPad by clicking on from here (you can do this from computer) and enter your Serial Number when requested.
Step 3: Then open Cydia and add the repo: http://apps.iphoneislam.com. Locate "PhoneItiPad" and install it.
Step 4: You should now be able to make calls and send SMS messages.
Here is a demo in action:
WARNING: Serial number is the unque identity of your iPad, you should think about it before giving it out to anyone.
Also, this is iOS 4 only. Don’t try it on iOS 5.