going to canada with tmobile phone

[hobey19]

i will be spending about two weeks in canada this summer, and i plan on taking my recently acquired tmobile mda with me. i have read about the $.49/min for roaming calls made within canada to canadian phones, and the $.69/min calls to america. the thing is, i only have a data plan on my phone right now, as my cell service is still through alltel.

what i am looking for is the best way for me to go about using the mda in canada. i read about buying prepaid sims, but i am not sure what the best route is since i need to call people both in canada as well as america while i am there.

the biggest issue, however, is that since i am on an exclusively data plan, i need to know if there are sims that allow me data access in canada? i am not terribly concerned about the phone aspect as i don't even have a voice plan right now. i am primarly interested in the most economical way to use this up north

thanks in advance for any help
craig