I have a Canon PowerShot S1 IS and it is really nice for the most part. It is a little slow to focus if you use the autofocus, which makes any moving aircraft or action shot difficult to time. It took me several tries at an airshow this summer to get some good shots of the RCAF Snowbirds and a B-17. I haven't got too far into using the manual focus yet or the burst mode. A bit more practice with following the aircraft while it takes the picture will help though. Faster memory cards would probably help somewhat too.
On the other hand, the image stabilization works very well. I have a couple of photos with at maximum zoom taken without a tripod and they look pretty good.
Maybe when I get home, I wil post a couple of samples.
goates