Gyroscopes the size of a grain of salt could mean accurate navigation on devices much smaller then previously possible. The article talks about how they could be used on phones to accurately navigate in buildings after losing the GPS signal. Such a targeting system could be used to make a crazy scary cluster-bomb; perfect distribution of the bomb-lets for optimal radial destruction, or individual targeting of each person in range.
"Israeli researchers have created the tiniest-ever optical gyroscopes, as small as a grain of sand, but still maintaining the keen accuracy of their counterparts hundreds of times larger. Optical gyroscopes are generally used for navigation in airplanes, ships and satellites, in which they track movement without reference to external navigation points, by measuring the vehicle’s rotation rate and linear acceleration. This is called inertial navigation. It’s extremely accurate but, up until now, only possible in gyroscopes and weighing two to three pounds.
Made possible by semi-conductor lasers measured in micrometers, these nanogyros are a different animal than the gyroscopes in the current generation of cell phones. They can continuously calculate the exact position of the object they’re installed in without needing to refer to external references the way GPS relies on satellites. Developer Koby Scheuer, a professor at Tel Aviv University, says the nanogyros “have compact enough dimensions to be integrated in small electronic devices.” That means if you’re in a tunnel and your GPS device isn’t working, this little guy will still know your precise location. Sounds a lot simpler than tracking lightning pulses to navigate underground."