You just gave me an even stronger argument for the 40D. I'm trying to save up for one now. I took shots of the angels at the great state of Maine airshow in Brunswick a few weeks ago with a Powershot S3 with a teleconverter lens. Didn't really get any great shots, I was testing aperture settings and had them down too low for the shutter speed. Just another way dyslexia sucks because ap settings seem counterintuitive to me.
1 pointer I do have that seemed to work for me was keeping my telephoto zoomed out to get a track on them and then zooming in leading them just a hair to find the shot.
Good luck and keep shooting.
That should give us nice photos for relatively not much money. My 40d camera and Canon 17-55 IS was a much more expensive set up.

