Motorola unveiled a full-size foldable keyboard for wireless phones on Monday. Difficulty typing on the 10-digit keypad of most mobile handsets has hampered the acceptance of wireless Internet services and other mobile applications, analysts say. The new iBoard keyboard was designed in collaboration with Think Outside, a private Carlsbad, Calif., company that developed a similar folding keyboard--called the Stowaway--for handheld computers. The iBoard, expected to retail for about $100, works with Motorola i85s and i50sx Internet-ready phones. Nextel Communications, a major wireless service provider and large Motorola customer, said it would begin selling the iBoard to its subscribers.