This month, a slow-swimming robot known as Spray will attempt to glide roughly 2,484 nautical miles across the Atlantic, from the southern tip of Greenland to the coast of Spain. An autonomous underwater vehicle, or AUV, Spray is a joint venture between the Woods Hole Oceanographic Institution in Massachusetts and the Scripps Institution of Oceanography in California. When deployed, it will act as an aquatic sentinel, gathering data on temperature, currents and salinity that will help scientists better understand the role of oceans in regulating the global climate.

“Ever wish you had a tool that could prove your suspicions were valid?” Bluewater Security Professionals asks on its Web site (bluewatersecurityprofessionals.com). "Next time you sense suspicious activity with your vehicle, make sure (the $435 PTS Tracking System) goes along for the ride. The site includes “hints” on where to put the GPS antenna—mostly in places where it wouldn't be seen. But forewarned is forearmed: Here are some of the spots where a GPS unit is likely to be stashed.