To use Live3G, you need to create a free My EyeTV account.

Register to use My EyeTV via the EyeTV 3.3 application on your Mac: In the iPhone section of the EyeTV Preferences, click the button to change My EyeTV account settings. You can create a new account here, or use the account you previously created to receive TV Guide data.

See this article for more details.