In AZ, summertime thunderstorms generally pop lightning from the same area.. I was going to try to build a Radio Shack arduino circuit, better for capturing daytime lighting, but also effective at night:
http://www.flickr.com/photos/iaincaradoc/sets/72157621660951255/I always try to use LiveView for focus as I have found that the Infinity mark on the lens barrels (on L lenses) are about 1/8" too far and therefore past focus. Liveview enables you to focus on a distant point of light (then click your lens to Manual Focus)
Also, AWB does a terrible job estimating the sky color temp, so I shoot Raw, then Tungsten in the city or Daytime for remote locations. Using RAW allows better post-color correction (I tend to more blue-grey clouds and sky)
Here are my lightning shots, hoping for some storms in the coming months
http://www.flickr.com …56964051%40N00&ss=2&s=int
another option is to use the Video mode of the camera - at 30fps you will catch the strike... I've done it with my S80 P&S