To "unbrick" an iPod Touch or iPhone, use the below instructions:

To restore your iPhone or iPod Touch, hold down the Power and Home buttons on the device until the Apple logo appears on the screen (be sure your device is already plugged into your computer, and that iTunes is running!), at which point you can let go of the Power button-- but keep holding the Home button. When you see the "Connect to iTunes" logo appear, you may let go of the Home button, and use iTunes to restore.