WASHINGTON, D.C. – The 2012 Tag Challenge calls on technology enthusiasts from several nations to set their sleuthing skills loose on a mock gang of jewel thieves in an international search contest to take place Saturday, March 31.

The social gaming contest will have participants use technological and social resources to locate and photograph five “suspects” in five different cities—Washington, D.C., New York City, London, Stockholm, and Bratislava—based only on a picture and a short description of each one.

The first person to upload pictures of all five suspects to the Tag Challenge website will earn international bragging rights—and a cash prize of $5,000.

From Robert Marus: Mayor Vincent C. Gray and officials from the United Nations Environment Programme (UNEP) today announced that the organization has named Washington, D.C., as the North American host city for World Environment Day (WED) 2012. With the regional theme, “Unite for a Sustainable D.C.,” UNEP invites area residents and organizations take part in energy-efficiency and sustainability activities during the six weeks linking Earth Day on April 22 and WED on June 5.