For limited time only RIM has made available the BlackBerry PlayBook Back-at-school offer. If you purchase a new BlackBerry PlayBook before September 22nd, you’ll get a $100 MasterCard Prepaid Card. This exclusive offer is only available to current BlackBerry smartphone customers who are legal residents of US/CA. It is also only available for a limited time, so make sure you get your PlayBook before the deadline! For more info on how and where to get your PlayBook, check here.