iPass is a simple to use VB application used to crack and output an iPhone, iPod or iPad's passcode (providing it's a 4 digit one)
Download redsn0w and place redsn0w.exe in /builds/common/files/tools/redsn0w/
Copy the contents of /builds/common/ to the rev1.2 folder and run iPass.exe
All credit goes to fallensn0w for the use of MobileDevice.dll, And to the iPhone Dev Team for redsn0w (not bundled here)