Sure, you can pop the SIM in, but will it connect? Looks like the J230i is a Dual band 900/1800 Mhz phone, which makes sense for Australia since those bands are used there. In Canada, GSM-1900 is the primary band used in urban areas, with 850 as a backup, and GSM-850 is the primary rural band. Since the J230i doesn't cover either of those bands, it won't work in Canada.

The similar Sony Ericsson J230a is Dual band 850/1900 Mhz and is made for use in North America.

Hope this helps.