Lightningmaps.org. Check it out.

[randomness]

Lightningmaps.org is a visualization of lightning data collected by a lightning detection network set up by a volunteer community of detector station operators.

They include instructions on how to set up your own station. "If you are not from Germany, Austria, or Switzerland you can even get a complete controller kit, a complete amplifier kit, ferrite rod antennas, and a gps modul for cost price, if desired."

Their real time map looks particularly cool when you turn "Stations: on".