1. A method of determining locations and/or activities of a user participating in a social networking service, the method executed by a computer system and comprising: automatically determining a first user visit of a first user at a positional destination via a first user electronic device; automatically determining a location of the positional destination via the first user electronic device; receiving a user activity at the location through the first user electronic device, wherein the user activity is manually entered by the first user at the first user visit at the positional destination; automatically determining a first context for the first user visit and user activity; automatically tagging the location with the user activity and context information from the first context, and storing the tagged location in a location database; automatically determining a second user visit at the positional destination via the first user electronic device; automatically delivering via the first user electronic device a request for manual confirmation of the user activity being performed for the second user visit; receiving the manual confirmation of the user activity for the second user visit to the positional destination; automatically determining a second context for the second user visit at the positional destination; automatically updating the context information of the tagged location from the second context; for each of a plurality of automatically determined further user visits at the positional destination, automatically determining a potential for the user activity based upon a comparison of a corresponding further context automatically determined for the each of the further user visits to the context information; automatically presenting the user activity to the first user through the first user electronic device for manual confirmation of the user activity through the user device at each of a plurality of further user visits at the location; automatically updating the context information of the tagged location from the further context of each of the further user visits; automatically learning the user activity by automatically associating the user activity with the location and the context information after receiving the user activity for the plurality of further user visits at the location; automatically deducing that the first user is participating in the learned user activity upon future user arrivals at the location as a function of comparing the context information to a future context of each of the future user arrivals, without receiving any manually entered confirmation or manually entered additional user information; a server computer of the computer system automatically sharing via a communication network to a second user electronic device of a second user participating in the social networking service that the first user is participating in the learned user activity upon the automatically identifying that the first user is participating in the learned user activity at each of the future user arrivals at the location; wherein each of the first context, the second context, the further context, and the context information comprises at least one of: a time of day, a day of a week, a calendar date, a preceding user activity to the user visits, a weather condition, people accompanying the user, or community member activity bias information for the positional destination.