Here is how to UNLOCK your samsung X497 (Cingular) ...now you can use it w/ any GSM service Provider!!! I HAVE PERSONALLY done this and I KNOW IT WORKS...
1. PUT IN A SIM CARD THAT IS NOT A CINGULAR sim card!!!!
2. at the "wrong card" screen press *2767*3855# something will pop up and disappear...leave your phone alone for 45 seconds and it will restart automatically.
3. It will start up and it will look like it is unlocked but ITS ONLY TEMPORARY!
4. Now press *7465625*638*00000000*00000000#....some message will pop up and disappear...
5. Now press #7465625*638*00000000# and a message about network lock INACTIVE..and now your phone is UNLOCKED FOREVER!!!! (your welcome!)
6. to make sure its unlocked press *#7465625# ...this is only to check...this code doesn't do anything else....you don't need to do this step if you don't want to..