Apple - Error message "iPod is disabled. Try again in 22,236,924 minutes."

No harm done, that is if you have a backup on iTunes.
The Apple Support pages tell you can reset the block by restoring it within iTunes.

If you cannot remember the passcode, you will need to restore your device using the computer with which you last synced it. This allows you to reset your passcode and resync the data from the device (or restore from a backup). If you restore on a different computer that was never synced with the device, you will be able to unlock the device for use and remove the passcode, but your data will not be present. Refer to Updating and restoring iPhone, iPad and iPod touch software.