When you're shooting you should always try and remember that one of the most important things to get right is the focus, as it's one of the few things that can't really be fixed in post-processing.
You might be able to achieve some kind of artistic effect if you mess around a bit but it's not really worth it IMO.
I'm aware of focusing Mark, it is after all the most basic but one of the most vital parts of photographing to get right. Like I said, it was an Airshow and the ground was busy...getting bumped into was a major concern and there was queues to get into some ground attractions, so I was being hurried along.
Anyway thanks for the advice though, I'm gonna try see if I can do anything artistic with it.