Method of real-time navigation for a mobile environment

A method of providing navigational information to a user connected in real-time, such as through a wireless telephone, PDA, or other device. The method provides navigational information to the user (202) by - establishing a real-time connection between a server (212) and the user; - receiving location information for the user from the server; - determining the uncertainty in the parameters that are needed to provide navigational information to the user; and - providing navigational information to the user, based on said uncertainty.