What type of BB are you using ?
Since MIKE iDEN BBs (7510.7520.7100i) are not compatible with sms
Well, you can receive ( i just tested with my 7510) , but no menu for "Compose SMS" or "SMS xxxxxx" in contacts
If you are using a PCS BB (7250,8700,7130) you should have the same functionnality as a normal phone
And Text messaging fees, if you have the latest unlimited sms function (code SMSGULD10) will be 0$ for reception and sending
But, if you use the email address instead (to send), well that goes under your data package
note that SMS sent from the TELUS website (without callback #) or by email, they arrive without a sender
With sufficient thrust, Blackberrys can fly