A handheld personal unit that can estimate a user's position in 3-dimensional space by determining a horizontal position and an altitude. GPS or assisted GPS can be used to determine the horizontal position, while barometric pressure assisted altimetry can be used to determine altitude accurately enough to localize the user to a particular floor of a particular building, and many times to a particular room. An artificial intelligence system can access one or more databases to provide data to the user that is related to the user's position in 3-dimensional space. This data can come from a database either stored in the handheld device or stored at a separate remote location. If a remote location is used to provide data and current barometric pressure (and possibly GPS assist), this station can access other remote stations, as needed, to supply the information. The handheld unit and/or the remote station can optionally access the internet to seek information related to the user's location in 3-dimensional space.