I'm currently testing this phone for my work. Im personally using a T-Mobile blackberry. My question is, can I use my T-Mobile simcard on this phone so I dont have to carrier 2 blackberry's around with me?

Nope ... the 8830 is CDMA "only" in the USA and GSM (900/1800) for overseas.

As the US only supports 850/1900 GSM, putting in the T-Mobile sim (in the USA) would accomplish very little ...

/BD