Hey Paul,
As far as the noise goes, shoot at ISO 100 whenever possible. The first lightning shots were shot at ISO 100 and I didn't notice any objectionable noise. With these, I didn't think to check the ISO, and when I checked, I saw that I had shot them at ISO 400. It should also be noted that I had my Noise Reduction on "Normal". Next time I'm going to put it on "High" and see if that helps reduce the noise as well.
Ironically, I've shot indoor shots without flash at ISO 800 and 1000, and the noise wasn't as bad as it is in these. Go figure.
I will definitely stay away from that spot behind the trees whenever there's a storm brewing, but I gotta admit, I'm curious to see what's out there that draws the lightning.
Congratulations on you D70s!!! It's always exciting getting new gear.
I'm still playing with White Balance, noise reduction, and I recently discovered that the D200 has two JPG settings - "Size Priority" where the files are compressed to about the same file size, and and "Optimal Quality" which is supposed to have less compression and better image quality. So far both settings give me image files between 3.5 and 4.5 megs. The only difference I've seen is that my frame counter went from 335 to 224. Like I said, I'm still learning!
Thanks for the comments buddy!