The cellphone is actually a very complicated radio that communicates with the cell tower in the area.
*3370# - Reserve battery in Nokia Phones
Many Nokia phones come with a reserve battery. To activate the battery, key-in *3370# your cell will restart with this reserve and your instrument will show a 50% increase in battery. This reserve will get charged when you charge your mobile next time.
More Mobile Facts
In Britain on January 1st 1985, the first call on a mobile phone was made by Ernie Wise, comedian and one half of the famous duo Morcambe and Wise.