T-Mobile, not Verizon is behind a very valuable location-based service called Personal Coverage Check. On your phone or on the Web the user keys in an address and gets back a thematic map of coverage of the local area, not the over generalized ones typically on brochures or websites. PC Magazine staff found it quite accurate save in Manhattan and asked other carriers why they did not offer such a tool. Only Cingular said it was updating its maps soon. The data, says the PC Magazine article, is updated weekly. Significant Уsmall printФ explains that the maps are not guarantees of service and that coverage can be impacted by a number of factors. Fair enough; itТs a great start!