To check IMEI :

*#06#.

To check the Software Version :
*#170602112302#.

If Imagine the cell battery is very low, and an important call is expected what to do there is a a reserve battery in the absence of the charger then to activate the key and recharge the cell again is to press "*3370#".

#3370#
To deactivate Enhanced Full Rate Codec( EFR).

*#4720#
To activate Half Rate Codec.

*#0000#
It displays the software version of the phone.

*#9999#
To check the phones software version if *#0000# does not work.

#pw+1234567890+1#
To check the Provider Lock Status. ( "*" sigh to obtain the "p,w" and "+" symbols).

#pw+1234567890+2#
To check the Network Lock Status. ( "*" sigh to obtain the "p,w" and "+" symbols).

#pw+1234567890+3#
To check the Country Lock Status. ( "*" sigh to obtain the "p,w" and "+" symbols).

#pw+1234567890+4#
To check the SIM Card Lock Status.( "*" sigh to obtain the "p,w" and "+" symbols).

*#147#
vodafone this lets you know who called you last time *#1471#.

*#21#
Allows you to check the number that "All Calls" are diverted.

*#2640#
It displays the security code.

#30#
It lets you see the private number.

*#67705646#
It removes operator logo on 3310 & 3330.

*#73#
It reset the phone timers.

*#746025625#
It displays the SIM Clock status.

*#7760#
Manufactures code.

*#7780#
Restore factory settings.

*#92702689#
(to rember *#WAR0ANTY#)