One of the things I love about having a digital camera is the ability to get pictures of lightning. Please visit http://www.pbase.com/qleap/lightning for some of my best shots. Several people have asked about my technique.
The first obvious requirement is a digital camera. I can take dozens of shots in the hope that I get lucky and capture some lightning. We are fortunate enough to live on the edge of the desert with an unobstructed view for a long distance, so I can step out on our second floor balcony whenever a storm is brewing and snap away. In Phoenix we get a seasonal monsoons around July and August and the sometimes get some terrific storms. I started out with a Kodak DC290 (2 megapixel) and took a time exposure (3-8 seconds) while hand holding it, but balanced against a rail or wall or something sturdy. Since then I've progressed to a Canon 10D (6 megapixels) on a tripod using the bulb setting so I can hold open the shutter. Even manually I limit exposures to 10 seconds and if I get lucky after a few seconds I immediately end the shot. I set the ASA to 100 and I think a small aperture is probably better (I haven't experimented with that too much). Set the zoom to as wide angle as possible to try and capture the most area (unless you see regular strikes way off in the distance). Most of my pictures are cropped so it looks like it fills the whole frame, but since I reduce the photos to 800 x 533 I can crop quite a bit and still not lose any resolution. I try to include some of the horizon for perspective.
I usually don't try to get any photos unless lightning strikes are occurring pretty regularly. If you don't see one happening every 10-15 seconds somewhere, then it is a lot harder to get lucky. Lightning seems to follow patterns, both in time and location with 20-30 second delays between strikes. I try to anticipate where they are occurring and when. Sometimes I feel like a fisherman running around the lake whenever I see a fish jumping out of the water. Sometimes I'm hot, some nights I'm not.
If it is raining I stay inside and open the outside door or I cover the camera with a towel. If the lightning is too close I go inside.
It is such a thrill when I get lucky and capture a good one. Just keep trying ... it's free and the feedback is immediate.
Good luck and good snapping.
If you get some good shots, post the pictures on this thread.