Canon 30D, tripod
The blog post relates this much more dramatically, but you've already seen the image, so...
In short, I was doing something that I wasn't supposed to do, and knew better. When I was attempting to photograph a distant electrical storm and it petered out, I noticed that the clouds almost directly above me were starting to develop their own activity, so I began aiming the camera skyward. I captured a lot of cloud-to-cloud bolts, not even producing thunder, but then came the single ground strike, lighting up the entire area and producing one hell of a bang only a fraction of second later – from the brief delay, I can only assume it struck within a couple hundred meters. This was not good, since I was standing out in a very exposed area next to a metal tripod. Let me be blunt and direct: don't do this.
Notable here is that, aiming almost straight up, you are seeing up the length of the lightning – the portion at the right edge of the frame is hundreds or thousands of meters closer than the thin tendrils spreading out underneath the clouds. The starburst glares along the bolt are a nice touch.
Also consider that this was a wide-angle shot at 19mm focal length – the kind that shows the whole room or a broad scenic area, and thus makes things in the frame seem smaller than real life. And this was the only ground-strike of the entire thunderhead, which didn't even produce rain.
But while we're here, I'll include an animated gif showing twelve frames almost immediately before, all full frame (as is the big image.) I was shooting 10-second exposures with about 10 seconds in between, and capturing this much activity. I'd had adequate warning...