Operating systems: Compatible with iPhone, iPod touch, and iPad. Requires iOS 4.2 or later.
What is it and how is it of use to journalists? Sonar allows you to see which of your contacts are nearby. It could be a particularly handy way for journalists attending press conferences, events and meet-ups to find out if there are key people in the vicinity.
The iPhone app first asks you to connect your Foursquare account, which provides the list of possible venues in the area. You can then connect your Twitter, Facebook and LinkedIn accounts.
What could be potentially really useful is the ability to see second degree contacts, such as someone who is not connected to you directly but with whom you share Twitter, LinkedIn or Facebook contacts.
Reviews: It gets 3.5 stars in iTunes App Store.
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