HI yes you can use your rogers sim in any Blackberry curve 8520 mobile only if it is unlocked one .Else if the phone is locked to some other network provider then until you unlock it you can't use it with your old sim ..You can easily unlock your phone using sites like UnBBlock.com here they are rendering unlock code for all blackberry mobile models at reliable cost .After unlocking the phone you can freely use it with any GSM sim ...