Might be us, but we have always found lightning detection a snap: see giant flash, hear thunderous roar. Eureka! Lightning detected. Apparently the Nokia software described by a recent patent app will use the handset's radio receiver to detect the electromagnetic pulse sent out by the lightning and then warn the user of any potential danger. We could see this being a useful feature for brightly-clothed adventure types and park rangers, but it may be a tough sell to the average Joe. If nothing ever comes to pass with this patent application, there is always the old "one-steamboat" system, where five steamboats is roughly equal to one mile away.