Could i break an agreement with fido? ( Canadian phone company )

Hey, I had a really rare question,
I have a 2 year agreement with fido,
I have a lg neon and i got it last year in october and i have a plan since april 2010.
Now i wanted a blackberry and i wanted to see if i could like change plans, or like change phones, since
I dont know much about phones i honestly dont know how this works,
Could i break a agreement and go with a blackberry one?
Or do i have to like, change phone company's and go with rogers? Chatr.. etc
What can i do? Any suggestions?
I really did wonder this and im trapped