*#06# displays the IMEI – the serial number – of your phone.
*#0000# displays the firmware and its date.
*#92702689# (*#war_anty) displays the “warranty-menu” of your phone.
*#2820# (*#bta_#) displays the bluetooth-address of your device.
*#62209526# (*#mac_wlan#) displays the MAC-address of your phone it works just for the Wifi phones.
* Holding # for three seconds on the home screen you change the active profile to silent or back.
* By pressing 0 (zero) for three seconds on the home-screen you easily can open the web browser.
* By pressing the Menu/Home key for three seconds you open the task manager, which shows all opened applications.
Nokia reset codes (Be very careful, resets lead to data loss)
*#7780# (*#rst_#) does a soft-reset to your phone.
*#7370# (*#res_#) does a hard-reset to your phone.