The iPod Touch is a relatively small device, so if you're concerned that it may be lost or stolen, you can link your device with a free Find My iPod Touch MobilMe account and keep track of your Touch's location in case of a mishap. This can also give you peace of mind, as you can then remotely access your Touch and erase any sensitive data on it that you don't want others to see it the device ends up in the wrong hands.
Open your computer's Web browser and navigate to the MobileMe login page (see Resources).
Type your MobileMe account email and password in the spaces provided and click the "Sign In" button to sign into your MobileMe account.
Allow several minutes for the Find My iPod Touch window to load. The approximate location of your iPod touch is displayed in the Web browser once Find My iPod Touch locates your iPod.