Get ready to add another big time e-reader partnership to the list: iRex is set to announce later today a deal that will bring its latest DR800SG E-Ink slab to Best Buy with unlimited Verizon 3G data on board. The $399 e-reader with 8.1-inch touchscreen arrives as rumored with the ability to wirelessly download digital books from Barnes & Noble's e-bookstore in addition to over 1,100 newspapers from Newspapers Direct -- it'll also handle any books downloadable in the ePub format. The 3G