The Social Desktop plasmoid, showing "Near", "Friends" and "News" is using my own location to find the "Near" users.

My own location is visible for me calling "https://API-KEY@api.opendesktop.org/v1/person/self" as described in http://www.freedesktop.org/wiki/Specifi ... es#getself

This location is not my real location, but the location of the internet access server of my provider. I would like to set my real fixed location of my home workstation. Is that possible?

Would it be possible for mobile device users, to set the location from the mobile devices' GPS instead of the providers access server location?

In this case, you need to file a feature request at bugs.kde.org, requesting that the capability be added to the KDE OCS implementation to support this.