Palm continues to broaden its Windows Mobile lineup with the Treo Pro, an unlocked Windows Mobile 6.1 Professional smartphone aimed at corporate networks and at individuals who prefer the unlocked, unsubsidized route. In a first, Palm is releasing the Treo Pro only as an unlocked handset here in the U.S. (The Treo 680 and the Palm Centro have been available unlocked, but alongside carrier versions.) In testing the Treo Pro, it became clear that the company has learned from many of its prior design and interface mistakes with the 700w, the 700wx, and the 750 Treo smartphones.