One word: Don't
I remember when data was unlimited, then $30 for 6 GB, I now have 5GB, 400 minutes daytime, unlimited local weekend minutes, 10 Favorites for $50 a month. Each time I was a sucker for the "shiny' new phone. Now data rates are skyrocketing and whenever I call Telus about a phone upgrade they say they have a data plan more in touch with my needs, for waay more $$ for less features ... but hey I get the shiny new phone.
In reality, the shininess wears off of the new phone in a hurry and now you're stuck with a phone bill that costs more than the phone at the end of the two years.