cant say for sure since tax laws differ in canada compared to the US, but since i use my BB as a communications device for my small, licensed business, any and all purchases and bills related to my device i deduct annually.
it doesnt mean i dont take personal calls on it, but technically it's for business, and how people may give out their business number to friends and family, i also do so with mine. i do have a separate BB on another account just for personal use, too, which i do not deduct from my annual income tax.
but as the guy above said, best ask your tax advisor for laws specific to your locale.
