The original BlackJack may not have all of the flashy features its next-generation sibling has, but it still packs a punch for a smartphone. It runs on Windows Mobile 5.0, has a QWERTY keyboard, multimedia capabilities, a 1.3 megapixel camera and microSD memory card slot.
Links:
[1] http://www.fiercewireless.com/special-reports/samsung-blackjack-ii-sgh-i617-top-selling-smartphones
[2] http://www.fiercewireless.com/special-reports/5-top-selling-smartphones