SpotWalla is a location sharing service with some excellent privacy settings to ensure that you only share your personal data with those that you have given permission.
SpotWalla users can share their location information via trips and / or location pages. Tracks of your trips can be shared on their own Google Map and can be embedded on your own website or blog. Location pages allow multiple users to share their last known location on a single Google Map.
The SpotWalla home page features links to the most popular tracks created with the service. You can also choose to view the most recent and the most active tracks.
With SpotWalla you can define secure zones in which your location will never be displayed. You can set-up secure zones for your home, your place of work or any other location. Once you have defined a secure zone your location will not be shared when you enter those areas.