NOTE: This video only applies to firmwares 2.0 and above. If you're not on those firmwares, you need to upgrade anyway. If you've been trying to get into DFU mode, but can't, or you think you're in DFU but keep getting error messages while restoring, this video should solve all your problems. It was recorded using PwnageTool, so all of the timing should be correct. Follow the instructions, and you're good. Download here.