HI you can't use smart or globe network sim in your sidekick mobile until you unlock it from t-mobile network ...You can easily unlock it using sites like OnlineGSMUnlock.com they are providing unlock code for all mobile models at reliable cost ...You first verify that whether the code is available for your mobile model ,country and network provider .If yes then pay for it and unlock your phone then freely use it with smart or any other GSM sim ...I haven't purchase any mobiles from Philippines so i am not aware about how much will it cost to purchase a sidekick mobile ...