HTC (High Tech Computer) has developed a smartphone that's just a half-inch thick, or 1.3 centimeters. It's available now in the U.S. from Cingular Wireless. <A HREF="http://www.cio.com/blog_view.html?CID=24793">The Cingular 3125 Smartphone</A> is a slender clamshell handset that runs on Windows Mobile 5.0, enabling it to compete with the Blackberry's push email service through its Outlook Mobile software.