The US Census Bureau is required to assess the nation's population and demographics every 10 years, and the next census will take place in 2010. In preparation for the census, 140,000 address canvassers or "listers" have begun fanning out across their assigned regions to update and verify addresses. The listers verify existing addresses, add new addresses, and document dwellings that might include multiple residents. This year, for the first time, canvassers are equipped with a handheld computer that includes built-in GPS. The GPS (shown in photo) was custom-designed for the census by the Harris Company, and built by HTC. Originally intended for the main census, it appears that use of the handheld computer/GPS will be limited only to this year's listing phase, due to training and technical constraints. Image © Harris Co.