These SIMs are on T-Mobile and will work with any unlocked Rogers/Fido phone, plus new HSPA handsets from Bell and Telus and CDMA handsets with GSM modes (e.g. Storm, Tour).
I've used them on my unlocked Bell Blackberry Storm and unlocked iPhone while traveling in the US to save on Roaming charges. T-Mobile rates are as low as 10 cents/minute nation-wide and have unlimited calling options.
For Prepaid options: http://www.t-mobile.com/shop/plans/prepaid-plans.aspx
347 Area Code - $30 CAD
I have a T-Mobile SIM with $15.96 USD credit that expires in April 2010.
The number is in area code 347 (New York City), but can be changed for free by calling T-Mobile in 5 months.
916 Area Code - Gold Member - $150 CAD
T-Mobile SIM with $128.51 USD credit that expires in July 2010.
The number is in area code 916 but can be changed for free immediately.
It's also a Gold Member account so you only need to refill $10 each YEAR to maintain the account and balance.
All comments are my own opinion and do not reflect the views of my employer or affiliated groups.