1. Sony Ericsson Secret Menu: -> * <- <- * <- * (-> means press joystick, arrow keys or jogdial to the right and <- means left.) You'll see phone model, software info, IMEI, configuration info, sim lock status, REAL time clock, total call time and text labels. You can also test your phones services and hardware from this menu (main display, camera, LED/illumination, Flash LED, keyboard, earphone, speaker, microphone, radio and vibrator tests)
2. IMEI Number: *#06# -For checking the International Mobile Equipment Identity.
3. Lockstatus: <- * * <- -SIM lock - Do not lock your phone if you don't know the unlock code. This is another good check before you buy any phone, especially second hand ones. If phone is SIM locked, you may not be able to switch to other GSM operators.
4. Shortcut to last dialed numbers: 0#
5. Shortcut to sim numbers: On main menu type a number and press #
6. If you change the language from default to any other language, then it may be difficult to switch to default language. The shortcut is very simple. Just press <0000>. <> stands for right arrow button or joystick.