Here's a good news for Pakistan..... Sygic GPS Navigation just released maps for Pakistan and is now available in Apple App Store. It's a turn by turn navigation and a must have GPS app. This app will work on all iOS devices (iPhone, iPod Touch, iPad). Please note iPhone 3GS having BaseBand 06.15.00 won't be able to use GPS as GPS doesn't work on this baseband.
To get it free you need to jailbreak your iOS device and it's also available in Installous. Search google to jailbreak your iDevice.