I'm on Cingular, not Rogers but I do use the Nuance Voice Control application and it's outstanding. I drive a lot for my job and it's great to be able to send a quick email or a quick SMS from my phone without looking.

Another great thing is the feature for adding a calendar entry without typing. One limitation is the 20 word email thing but it doesn't bother me too much as I'm not using this to write a novel. One great thign would be a single button verification (say the same one used to start the voice control) and a single button cancel button.