Thanks folks for your efforts and replies. I am overwhelmed by the responses. This is the first time I have posted like this on this forum and the responses have exceeded all my expectations. This is simply one of the most informative forums I have encountered. On other forums, not that I have post this issue there, i don't get much response. Thanks a million. You have given me much to think about and I am not in a hurry to make a purchase.
O'Neill thanks for your long reply. In reading it, I thought you have been reading my mail. My wife an I are recent enthusiasts photographers, only been a member of a camera club for our second year but it has really stretched us. This is the first year of seriously entering monthly club competitions (which are judged by Photographic Society of Queensland [PSQ] accredited judges, not club members) and I have already picked up seven awards (mainly merits but one highly commended) in 6 competitions. So this has spurred me on to want to achieve more with my photography. Hence the reason for looking at better glass. When I got our first 18-200mm EF-S lens I was impressed with the first outing (having had only kit lenses before). It's just a great walk around lens too and gives a great focal length range. We've photographed a few events in the last last year or two and this is such a great lens for these sorts of things where you need a good focal length range.
However, I want to start thinking about getting lenses that are more targeted to particular needs/types of photography (rather than the all rounders we have). The input I have received on this thread has been simply awesome, has helped a lot and is greatly appreciated. Keep it coming.