Ever wondered receiving your SMS, Messages, Twitter, Facebook and all iOS notifications simultaneously on your Mac and PC then Growl is the solution and by installing GrowlNotifier Jailbreak application on your iPhone, iPad or iPod Touch. GrowlNotifier is a free jailbreak tweak and very easy to setup. All you need to do is install the Jailbreak tweak from Cydia and configure the IP address for the PC/Mac you want to see the notifications. When you have configured the IP address rest leave it to GrowlNotifier as even it will show you the messages on PC/Mac when it is unlocked as well.
Source iDownload Blog
In order to get this Cydia App on your iPhone, iPad and iPod Touch, make sure you device is Jailbroken. Click here to tethered Jailbreak iOS 5 On iPhone 4, 3GS, iPad, iPod touch using RedSn0w.